diff --git a/src/Collection.php b/src/Collection.php
index 91e1dc0..64fd2ec 100644
--- a/src/Collection.php
+++ b/src/Collection.php
@@ -15,6 +15,7 @@
 use JsonSerializable;
 use Noctud\Collection\Exception\ConversionException;
 use Noctud\Collection\Exception\NoSuchElementException;
+use Noctud\Collection\Exception\NonReplayableSourceException;
 use Noctud\Collection\Exception\UnsupportedOperationException;
 use Noctud\Collection\List\ImmutableList;
 use Noctud\Collection\List\ListInterface;
@@ -546,6 +547,7 @@ public function windowed(int $size, int $step = 1, bool $partialWindows = false)
 	 * @template U
 	 * @param iterable<U> $other
 	 * @return ListInterface<array{E, U}>
+	 * @throws NonReplayableSourceException If the other iterator cannot be rewound
 	 */
 	#[NoDiscard]
 	public function zip(iterable $other): ListInterface;
diff --git a/src/Exception/ConversionException.php b/src/Exception/ConversionException.php
index 1971677..853570c 100644
--- a/src/Exception/ConversionException.php
+++ b/src/Exception/ConversionException.php
@@ -11,6 +11,6 @@
 
 use LogicException;
 
-final class ConversionException extends LogicException
+final class ConversionException extends LogicException implements NoctudCollectionException
 {
 }
diff --git a/src/Exception/IndexOutOfBoundsException.php b/src/Exception/IndexOutOfBoundsException.php
index 8758131..4acf3c1 100644
--- a/src/Exception/IndexOutOfBoundsException.php
+++ b/src/Exception/IndexOutOfBoundsException.php
@@ -11,6 +11,6 @@
 
 use LogicException;
 
-final class IndexOutOfBoundsException extends LogicException
+final class IndexOutOfBoundsException extends LogicException implements NoctudCollectionException
 {
 }
diff --git a/src/Exception/InvalidKeyTypeException.php b/src/Exception/InvalidKeyTypeException.php
index c0915bb..bd476da 100644
--- a/src/Exception/InvalidKeyTypeException.php
+++ b/src/Exception/InvalidKeyTypeException.php
@@ -11,6 +11,6 @@
 
 use LogicException;
 
-final class InvalidKeyTypeException extends LogicException
+final class InvalidKeyTypeException extends LogicException implements NoctudCollectionException
 {
 }
diff --git a/src/Exception/InvalidSequenceSourceException.php b/src/Exception/InvalidSequenceSourceException.php
index 88bbf51..411f75e 100644
--- a/src/Exception/InvalidSequenceSourceException.php
+++ b/src/Exception/InvalidSequenceSourceException.php
@@ -14,7 +14,7 @@
 /**
  * Thrown when a sequence source closure returns a non-iterable value.
  */
-final class InvalidSequenceSourceException extends LogicException
+final class InvalidSequenceSourceException extends LogicException implements SourceException
 {
 	public static function closureReturnedNonIterable(mixed $produced): self
 	{
diff --git a/src/Exception/NoSuchElementException.php b/src/Exception/NoSuchElementException.php
index 7ee8b1e..47537c7 100644
--- a/src/Exception/NoSuchElementException.php
+++ b/src/Exception/NoSuchElementException.php
@@ -13,7 +13,7 @@
 use Noctud\Collection\Collection;
 use Noctud\Collection\Sequence\Sequence;
 
-final class NoSuchElementException extends LogicException
+final class NoSuchElementException extends LogicException implements NoctudCollectionException
 {
 	use NamesItsSubject;
 
diff --git a/src/Exception/NoctudCollectionException.php b/src/Exception/NoctudCollectionException.php
new file mode 100644
index 0000000..f1ef2c6
--- /dev/null
+++ b/src/Exception/NoctudCollectionException.php
@@ -0,0 +1,23 @@
+<?php
+
+/**
+ * This file is part of the Noctud Collection.
+ * Copyright (c) Noctud.dev
+ */
+
+declare(strict_types=1);
+
+namespace Noctud\Collection\Exception;
+
+use Throwable;
+
+/**
+ * Marks every exception this library raises, so a single catch covers them all.
+ *
+ * An interface rather than a base class: each failure keeps the parent that describes it best
+ * - LogicException for all of them today - and a third-party collection built on this library
+ * can join the family without giving up the exception hierarchy it already has.
+ */
+interface NoctudCollectionException extends Throwable
+{
+}
diff --git a/src/Exception/NonReplayableSourceException.php b/src/Exception/NonReplayableSourceException.php
index 5176da4..ed412c1 100644
--- a/src/Exception/NonReplayableSourceException.php
+++ b/src/Exception/NonReplayableSourceException.php
@@ -14,7 +14,7 @@
 /**
  * Thrown when an iterable that can only be walked once is walked again.
  */
-final class NonReplayableSourceException extends UnsupportedOperationException
+final class NonReplayableSourceException extends UnsupportedOperationException implements SourceException
 {
 	public static function sequenceSourceAlreadyIterated(): self
 	{
diff --git a/src/Exception/SourceException.php b/src/Exception/SourceException.php
new file mode 100644
index 0000000..32a5876
--- /dev/null
+++ b/src/Exception/SourceException.php
@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * This file is part of the Noctud Collection.
+ * Copyright (c) Noctud.dev
+ */
+
+declare(strict_types=1);
+
+namespace Noctud\Collection\Exception;
+
+/**
+ * Marks the failures raised when walking a source rather than by what a method does: a
+ * source that refuses to hand back a fresh pass, or one that hands back something not
+ * iterable.
+ *
+ * Methods that walk a source declare this single type rather than the concrete exceptions
+ * behind it - which one surfaces depends on the source, not on the method called.
+ */
+interface SourceException extends NoctudCollectionException
+{
+}
diff --git a/src/Exception/UnsupportedOperationException.php b/src/Exception/UnsupportedOperationException.php
index 354412b..41c2ad3 100644
--- a/src/Exception/UnsupportedOperationException.php
+++ b/src/Exception/UnsupportedOperationException.php
@@ -17,7 +17,7 @@
  * Thrown when a mutating method is called on an immutable collection/map or when a
  * requested operation is not valid in the current state (e.g., removing from an empty list).
  */
-class UnsupportedOperationException extends LogicException
+class UnsupportedOperationException extends LogicException implements NoctudCollectionException
 {
 	use NamesItsSubject;
 
diff --git a/src/Sequence/Sequence.php b/src/Sequence/Sequence.php
index 3bddf27..e754f79 100644
--- a/src/Sequence/Sequence.php
+++ b/src/Sequence/Sequence.php
@@ -13,9 +13,8 @@
 use IteratorAggregate;
 use Noctud\Collection\Exception\ConversionException;
 use Noctud\Collection\Exception\IndexOutOfBoundsException;
-use Noctud\Collection\Exception\InvalidSequenceSourceException;
-use Noctud\Collection\Exception\NonReplayableSourceException;
 use Noctud\Collection\Exception\NoSuchElementException;
+use Noctud\Collection\Exception\SourceException;
 use Noctud\Collection\Exception\UnsupportedOperationException;
 use Noctud\Collection\List\ImmutableList;
 use Noctud\Collection\Map\ImmutableMap;
@@ -44,6 +43,10 @@
  * the second pass then throws NonReplayableSourceException instead of replaying an array
  * or re-invoking a producer, which is what you want when replaying would repeat a side effect.
  *
+ * NonReplayableSourceException and InvalidSequenceSourceException both implement
+ * SourceException, the single type every method below declares - which concrete
+ * one surfaces depends on the source, not on the method called.
+ *
  * Keys are positional: every pass yields fresh 0..n keys, whatever the source yields.
  *
  * Deliberately neither Countable (native count($seq) stays a TypeError by design;
@@ -236,8 +239,7 @@ public function onEach(Closure $action): Sequence;
 	 * still hands the collection back.
 	 *
 	 * @param Closure(E, int):void $action
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function forEach(Closure $action): void;
 
@@ -248,8 +250,7 @@ public function forEach(Closure $action): void;
 	 *
 	 * @return E
 	 * @throws NoSuchElementException If the sequence is empty
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function first();
 
@@ -257,8 +258,7 @@ public function first();
 	 * Returns the first element, or null if the sequence is empty. Pulls exactly one element.
 	 *
 	 * @return E|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function firstOrNull(): mixed;
 
@@ -269,8 +269,7 @@ public function firstOrNull(): mixed;
 	 *
 	 * @return E
 	 * @throws NoSuchElementException If the sequence is empty
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function last();
 
@@ -278,8 +277,7 @@ public function last();
 	 * Returns the last element, or null if the sequence is empty. Drains the sequence.
 	 *
 	 * @return E|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function lastOrNull(): mixed;
 
@@ -289,8 +287,7 @@ public function lastOrNull(): mixed;
 	 *
 	 * @return E
 	 * @throws NoSuchElementException If the sequence is empty or holds more than one element
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function single();
 
@@ -298,8 +295,7 @@ public function single();
 	 * Returns the single element, or null if the sequence is empty or holds more than one.
 	 *
 	 * @return E|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function singleOrNull(): mixed;
 
@@ -311,8 +307,7 @@ public function singleOrNull(): mixed;
 	 * @param non-negative-int $index
 	 * @return E
 	 * @throws IndexOutOfBoundsException If the sequence holds fewer elements than that or if the index is a negative int
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function elementAt(int $index);
 
@@ -322,8 +317,7 @@ public function elementAt(int $index);
 	 * @param non-negative-int $index
 	 * @return E|null
 	 * @throws IndexOutOfBoundsException If the index is a negative int
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function elementAtOrNull(int $index): mixed;
 
@@ -333,8 +327,7 @@ public function elementAtOrNull(int $index): mixed;
 	 *
 	 * @param Closure(E, int):bool $predicate
 	 * @return E|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function find(Closure $predicate): mixed;
 
@@ -345,8 +338,7 @@ public function find(Closure $predicate): mixed;
 	 * @param Closure(E, int):bool $predicate
 	 * @return E
 	 * @throws NoSuchElementException If no element matches the predicate
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function expect(Closure $predicate);
 
@@ -356,8 +348,7 @@ public function expect(Closure $predicate);
 	 *
 	 * @param Closure(E, int):bool $predicate
 	 * @return E|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function findLast(Closure $predicate): mixed;
 
@@ -368,8 +359,7 @@ public function findLast(Closure $predicate): mixed;
 	 * @param Closure(E, int):bool $predicate
 	 * @return E
 	 * @throws NoSuchElementException If no element matches the predicate
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function expectLast(Closure $predicate);
 
@@ -378,16 +368,14 @@ public function expectLast(Closure $predicate);
 	/**
 	 * Whether the sequence does not contain any elements. Pulls exactly one element.
 	 *
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function isEmpty(): bool;
 
 	/**
 	 * Whether the sequence contains at least one element. Pulls exactly one element.
 	 *
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function isNotEmpty(): bool;
 
@@ -396,8 +384,7 @@ public function isNotEmpty(): bool;
 	 * Stops pulling at the first match.
 	 *
 	 * @param E $element
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function contains(mixed $element): bool;
 
@@ -406,8 +393,7 @@ public function contains(mixed $element): bool;
 	 * Walks the sequence once, stopping as soon as none is left to look for.
 	 *
 	 * @param iterable<E> $elements
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function containsAll(iterable $elements): bool;
 
@@ -416,8 +402,7 @@ public function containsAll(iterable $elements): bool;
 	 * Stops pulling at the first element that does not.
 	 *
 	 * @param Closure(E, int):bool $predicate
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function all(Closure $predicate): bool;
 
@@ -426,8 +411,7 @@ public function all(Closure $predicate): bool;
 	 * Stops pulling at the first match.
 	 *
 	 * @param Closure(E, int):bool $predicate
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function any(Closure $predicate): bool;
 
@@ -436,8 +420,7 @@ public function any(Closure $predicate): bool;
 	 * Stops pulling at the first match.
 	 *
 	 * @param Closure(E, int):bool $predicate
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function none(Closure $predicate): bool;
 
@@ -447,8 +430,7 @@ public function none(Closure $predicate): bool;
 	 * elements to pull, which is why the cost has to be asked for explicitly.
 	 *
 	 * @return int<0, max>
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function count(): int;
 
@@ -457,8 +439,7 @@ public function count(): int;
 	 *
 	 * @param Closure(E, int):bool $predicate
 	 * @return int<0, max>
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function countWhere(Closure $predicate): int;
 
@@ -472,8 +453,7 @@ public function countWhere(Closure $predicate): int;
 	 * @param R $initial
 	 * @param Closure(R, E):R $operation
 	 * @return R
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function fold(mixed $initial, Closure $operation): mixed;
 
@@ -483,8 +463,7 @@ public function fold(mixed $initial, Closure $operation): mixed;
 	 * @param Closure(E, E):E $operation
 	 * @return E
 	 * @throws UnsupportedOperationException If the sequence is empty
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function reduce(Closure $operation);
 
@@ -494,8 +473,7 @@ public function reduce(Closure $operation);
 	 *
 	 * @param Closure(E, E):E $operation
 	 * @return E|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function reduceOrNull(Closure $operation): mixed;
 
@@ -505,8 +483,7 @@ public function reduceOrNull(Closure $operation): mixed;
 	 * @template TSum
 	 * @param (Closure(E, int):TSum)|null $selector
 	 * @return ($selector is null ? (E is int ? int : int|float) : (TSum is int ? int : int|float))
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function sum(?Closure $selector = null): int|float;
 
@@ -516,8 +493,7 @@ public function sum(?Closure $selector = null): int|float;
 	 *
 	 * @param Closure(E, int):(int|float)|null $selector
 	 * @throws UnsupportedOperationException If the sequence is empty
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function avg(?Closure $selector = null): float;
 
@@ -526,8 +502,7 @@ public function avg(?Closure $selector = null): float;
 	 * sequence is empty. Drains the sequence.
 	 *
 	 * @param Closure(E, int):(int|float)|null $selector
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function avgOrNull(?Closure $selector = null): float|null;
 
@@ -538,8 +513,7 @@ public function avgOrNull(?Closure $selector = null): float|null;
 	 * @param Closure(E, int):mixed|null $selector
 	 * @return E
 	 * @throws NoSuchElementException If the sequence is empty
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function min(?Closure $selector = null): mixed;
 
@@ -549,8 +523,7 @@ public function min(?Closure $selector = null): mixed;
 	 *
 	 * @param Closure(E, int):mixed|null $selector
 	 * @return E|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function minOrNull(?Closure $selector = null): mixed;
 
@@ -561,8 +534,7 @@ public function minOrNull(?Closure $selector = null): mixed;
 	 * @param Closure(E, int):mixed|null $selector
 	 * @return E
 	 * @throws NoSuchElementException If the sequence is empty
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function max(?Closure $selector = null): mixed;
 
@@ -572,8 +544,7 @@ public function max(?Closure $selector = null): mixed;
 	 *
 	 * @param Closure(E, int):mixed|null $selector
 	 * @return E|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function maxOrNull(?Closure $selector = null): mixed;
 
@@ -584,8 +555,7 @@ public function maxOrNull(?Closure $selector = null): mixed;
 	 * @param Closure(E, int):R $selector
 	 * @return R
 	 * @throws NoSuchElementException If the sequence is empty
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function minOf(Closure $selector): mixed;
 
@@ -596,8 +566,7 @@ public function minOf(Closure $selector): mixed;
 	 * @template R of mixed
 	 * @param Closure(E, int):R $selector
 	 * @return R|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function minOfOrNull(Closure $selector): mixed;
 
@@ -608,8 +577,7 @@ public function minOfOrNull(Closure $selector): mixed;
 	 * @param Closure(E, int):R $selector
 	 * @return R
 	 * @throws NoSuchElementException If the sequence is empty
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function maxOf(Closure $selector): mixed;
 
@@ -620,8 +588,7 @@ public function maxOf(Closure $selector): mixed;
 	 * @template R of mixed
 	 * @param Closure(E, int):R $selector
 	 * @return R|null
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function maxOfOrNull(Closure $selector): mixed;
 
@@ -639,8 +606,7 @@ public function maxOfOrNull(Closure $selector): mixed;
 	 *
 	 * @param Closure(E, int):string|null $transform Optional transform to apply to each element
 	 * @throws ConversionException When an element cannot be converted to string and no transform is provided
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	public function joinToString(string $separator = ', ', string $prefix = '', string $postfix = '', int $limit = -1, string $truncated = '...', ?Closure $transform = null): string;
 
@@ -650,8 +616,7 @@ public function joinToString(string $separator = ', ', string $prefix = '', stri
 	 * Convert to an immutable list, consuming one pass of the sequence.
 	 *
 	 * @return ImmutableList<E>
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	#[NoDiscard]
 	public function toList(): ImmutableList;
@@ -660,8 +625,7 @@ public function toList(): ImmutableList;
 	 * Convert to an immutable set (duplicates removed), consuming one pass of the sequence.
 	 *
 	 * @return ImmutableSet<E>
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	#[NoDiscard]
 	public function toSet(): ImmutableSet;
@@ -670,8 +634,7 @@ public function toSet(): ImmutableSet;
 	 * Convert to a primitive PHP array, consuming one pass of the sequence.
 	 *
 	 * @return list<E>
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	#[NoDiscard]
 	public function toArray(): array;
@@ -684,8 +647,7 @@ public function toArray(): array;
 	 * @param Closure(E, int):K $keySelector
 	 * @param ?Closure(E, int):V $valueTransform
 	 * @return ImmutableMap<K,V>
-	 * @throws NonReplayableSourceException If a non-replayable source has already been consumed
-	 * @throws InvalidSequenceSourceException If a Closure source returns a non-iterable
+	 * @throws SourceException If the source cannot produce a pass (already consumed, or not an iterable)
 	 */
 	#[NoDiscard]
 	public function toMap(Closure $keySelector, ?Closure $valueTransform = null): ImmutableMap;
diff --git a/tests/ExceptionHierarchyTest.php b/tests/ExceptionHierarchyTest.php
new file mode 100644
index 0000000..f53ebfd
--- /dev/null
+++ b/tests/ExceptionHierarchyTest.php
@@ -0,0 +1,107 @@
+<?php
+
+/**
+ * This file is part of the Noctud Collection.
+ * Copyright (c) Noctud.dev
+ */
+
+declare(strict_types=1);
+
+namespace Noctud\Collection\Tests;
+
+use FilesystemIterator;
+use Generator;
+use Noctud\Collection\Exception\NoctudCollectionException;
+use Noctud\Collection\Exception\SourceException;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use RecursiveDirectoryIterator;
+use RecursiveIteratorIterator;
+use SplFileInfo;
+use Throwable;
+use function Noctud\Collection\listOf;
+use function Noctud\Collection\sequenceOf;
+
+final class ExceptionHierarchyTest extends TestCase
+{
+	#[Test]
+	public function a_source_that_cannot_replay_is_caught_as_a_sequence_failure(): void
+	{
+		$generator = (static function (): Generator {
+			yield 1;
+		})();
+		$sequence = sequenceOf($generator);
+
+		$this->assertSame([1], $sequence->toArray());
+
+		$this->expectException(SourceException::class);
+
+		$_ = $sequence->toArray(); // phpcs:ignore SlevomatCodingStandard.Variables.UnusedVariable.UnusedVariable
+	}
+
+	#[Test]
+	public function a_source_returning_a_non_iterable_is_caught_as_a_sequence_failure(): void
+	{
+		/** @phpstan-ignore argument.type, argument.templateType */
+		$sequence = sequenceOf(static fn (): int => 42);
+
+		$this->expectException(SourceException::class);
+
+		$_ = $sequence->toArray(); // phpcs:ignore SlevomatCodingStandard.Variables.UnusedVariable.UnusedVariable
+	}
+
+	#[Test]
+	public function a_sequence_failure_is_also_caught_at_the_library_root(): void
+	{
+		/** @phpstan-ignore argument.type, argument.templateType */
+		$sequence = sequenceOf(static fn (): int => 42);
+
+		$this->expectException(NoctudCollectionException::class);
+
+		$_ = $sequence->toArray(); // phpcs:ignore SlevomatCodingStandard.Variables.UnusedVariable.UnusedVariable
+	}
+
+	#[Test]
+	public function an_eager_failure_is_caught_at_the_library_root(): void
+	{
+		$this->expectException(NoctudCollectionException::class);
+
+		$_ = listOf([])->first(); // phpcs:ignore SlevomatCodingStandard.Variables.UnusedVariable.UnusedVariable
+	}
+
+	#[Test]
+	#[DataProvider('libraryExceptions')]
+	public function every_library_exception_implements_the_root_marker(string $class): void
+	{
+		$this->assertTrue(
+			is_subclass_of($class, NoctudCollectionException::class),
+			sprintf('%s must implement %s', $class, NoctudCollectionException::class),
+		);
+	}
+
+	/**
+	 * @return Generator<string, array{class-string<Throwable>}>
+	 */
+	public static function libraryExceptions(): Generator
+	{
+		$src = dirname(__DIR__) . '/src';
+		/** @var iterable<SplFileInfo> $files */
+		$files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($src, FilesystemIterator::SKIP_DOTS));
+
+		foreach ($files as $file) {
+			if ($file->getExtension() !== 'php') {
+				continue;
+			}
+
+			// PSR-4 in reverse: src/Exception/Foo.php -> Noctud\Collection\Exception\Foo
+			$relative = substr($file->getPathname(), strlen($src) + 1, -4);
+			$class = 'Noctud\\Collection\\' . str_replace(DIRECTORY_SEPARATOR, '\\', $relative);
+
+			// class_exists() autoloads; interfaces, traits and functions.php fall out here
+			if (class_exists($class) && is_subclass_of($class, Throwable::class)) {
+				yield $class => [$class];
+			}
+		}
+	}
+}