diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index e3d66d18388c6..886bfb1e39b27 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -706,7 +706,7 @@ fn test_unstable_options_tracking_hash() {
     untracked!(ls, true);
     untracked!(macro_backtrace, true);
     untracked!(meta_stats, true);
-    untracked!(mir_include_spans, true);
+    untracked!(mir_include_extra_comments, false);
     untracked!(nll_facts, true);
     untracked!(no_analysis, true);
     untracked!(no_leak_check, true);
diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs
index 27e3913709231..cb4689b69de95 100644
--- a/compiler/rustc_middle/src/mir/pretty.rs
+++ b/compiler/rustc_middle/src/mir/pretty.rs
@@ -352,7 +352,7 @@ where
     for statement in &data.statements {
         extra_data(PassWhere::BeforeLocation(current_location), w)?;
         let indented_body = format!("{INDENT}{INDENT}{statement:?};");
-        if tcx.sess.opts.unstable_opts.mir_include_spans {
+        if tcx.sess.opts.unstable_opts.mir_include_extra_comments {
             writeln!(
                 w,
                 "{:A$} // {}{}",
@@ -377,7 +377,7 @@ where
     // Terminator at the bottom.
     extra_data(PassWhere::BeforeLocation(current_location), w)?;
     let indented_terminator = format!("{0}{0}{1:?};", INDENT, data.terminator().kind);
-    if tcx.sess.opts.unstable_opts.mir_include_spans {
+    if tcx.sess.opts.unstable_opts.mir_include_extra_comments {
         writeln!(
             w,
             "{:A$} // {}{}",
@@ -407,7 +407,7 @@ fn write_extra<'tcx, F>(tcx: TyCtxt<'tcx>, write: &mut dyn Write, mut visit_op:
 where
     F: FnMut(&mut ExtraComments<'tcx>),
 {
-    if tcx.sess.opts.unstable_opts.mir_include_spans {
+    if tcx.sess.opts.unstable_opts.mir_include_extra_comments {
         let mut extra_comments = ExtraComments { tcx, comments: vec![] };
         visit_op(&mut extra_comments);
         for comment in extra_comments.comments {
@@ -564,7 +564,7 @@ fn write_scope_tree(
             var_debug_info.value,
         );
 
-        if tcx.sess.opts.unstable_opts.mir_include_spans {
+        if tcx.sess.opts.unstable_opts.mir_include_extra_comments {
             writeln!(
                 w,
                 "{0:1$} // in {2}",
@@ -602,7 +602,7 @@ fn write_scope_tree(
 
         let local_name = if local == RETURN_PLACE { " return place" } else { "" };
 
-        if tcx.sess.opts.unstable_opts.mir_include_spans {
+        if tcx.sess.opts.unstable_opts.mir_include_extra_comments {
             writeln!(
                 w,
                 "{0:1$} //{2} in {3}",
@@ -639,7 +639,7 @@ fn write_scope_tree(
 
         let indented_header = format!("{0:1$}scope {2}{3} {{", "", indent, child.index(), special);
 
-        if tcx.sess.opts.unstable_opts.mir_include_spans {
+        if tcx.sess.opts.unstable_opts.mir_include_extra_comments {
             if let Some(span) = span {
                 writeln!(
                     w,
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 055ab2d9c1583..02597a9c0a677 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -1599,8 +1599,9 @@ options! {
         "use like `-Zmir-enable-passes=+DestinationPropagation,-InstSimplify`. Forces the specified passes to be \
         enabled, overriding all other checks. Passes that are not specified are enabled or \
         disabled by other flags as usual."),
-    mir_include_spans: bool = (false, parse_bool, [UNTRACKED],
-        "use line numbers relative to the function in mir pretty printing"),
+    mir_include_extra_comments: bool = (true, parse_bool, [UNTRACKED],
+        "include extra comments in mir pretty printing, like line numbers and statement indices, \
+         details about types, etc. (default: yes)"),
     mir_keep_place_mention: bool = (false, parse_bool, [TRACKED],
         "keep place mention MIR statements, interpreted e.g., by miri; implies -Zmir-opt-level=0 \
         (default: no)"),
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 3d237eb25cc9a..243cd15dec5fc 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -2363,6 +2363,7 @@ impl<'test> TestCx<'test> {
                     &zdump_arg,
                     "-Zvalidate-mir",
                     "-Zdump-mir-exclude-pass-number",
+                    "-Zmir-include-extra-comments=false",
                 ]);
                 if let Some(pass) = &self.props.mir_unit_test {
                     rustc.args(&["-Zmir-opt-level=0", &format!("-Zmir-enable-passes=+{}", pass)]);
diff --git a/tests/mir-opt/pre-codegen/spans.rs b/tests/mir-opt/pre-codegen/spans.rs
index 6ae9935eeb67b..4f24894dc7e7b 100644
--- a/tests/mir-opt/pre-codegen/spans.rs
+++ b/tests/mir-opt/pre-codegen/spans.rs
@@ -1,7 +1,7 @@
 // Test that the comments we emit in MIR opts are accurate.
 //
 // EMIT_MIR_FOR_EACH_PANIC_STRATEGY
-// compile-flags: -Zmir-include-spans
+// compile-flags: -Zmir-include-extra-comments
 // ignore-wasm32
 
 #![crate_type = "lib"]
diff --git a/tests/run-make/const_fn_mir/dump.mir b/tests/run-make/const_fn_mir/dump.mir
index ced170bbeee2f..ce273e34c47f6 100644
--- a/tests/run-make/const_fn_mir/dump.mir
+++ b/tests/run-make/const_fn_mir/dump.mir
@@ -1,45 +1,48 @@
 // WARNING: This output format is intended for human consumers only
 // and is subject to change without notice. Knock yourself out.
 fn foo() -> i32 {
-    let mut _0: i32;
-    let mut _1: (i32, bool);
+    let mut _0: i32;                     // return place in scope 0 at main.rs:4:19: 4:22
+    let mut _1: (i32, bool);             // in scope 0 at main.rs:5:5: 5:10
 
     bb0: {
-        _1 = CheckedAdd(const 5_i32, const 6_i32);
-        assert(!move (_1.1: bool), "attempt to compute `{} + {}`, which would overflow", const 5_i32, const 6_i32) -> [success: bb1, unwind continue];
+        _1 = CheckedAdd(const 5_i32, const 6_i32); // scope 0 at main.rs:5:5: 5:10
+        assert(!move (_1.1: bool), "attempt to compute `{} + {}`, which would overflow", const 5_i32, const 6_i32) -> [success: bb1, unwind continue]; // scope 0 at main.rs:5:5: 5:10
     }
 
     bb1: {
-        _0 = move (_1.0: i32);
-        return;
+        _0 = move (_1.0: i32);           // scope 0 at main.rs:5:5: 5:10
+        return;                          // scope 0 at main.rs:6:2: 6:2
     }
 }
 
 // MIR FOR CTFE
 fn foo() -> i32 {
-    let mut _0: i32;
-    let mut _1: (i32, bool);
+    let mut _0: i32;                     // return place in scope 0 at main.rs:4:19: 4:22
+    let mut _1: (i32, bool);             // in scope 0 at main.rs:5:5: 5:10
 
     bb0: {
-        _1 = CheckedAdd(const 5_i32, const 6_i32);
-        assert(!move (_1.1: bool), "attempt to compute `{} + {}`, which would overflow", const 5_i32, const 6_i32) -> [success: bb1, unwind continue];
+        _1 = CheckedAdd(const 5_i32, const 6_i32); // scope 0 at main.rs:5:5: 5:10
+        assert(!move (_1.1: bool), "attempt to compute `{} + {}`, which would overflow", const 5_i32, const 6_i32) -> [success: bb1, unwind continue]; // scope 0 at main.rs:5:5: 5:10
     }
 
     bb1: {
-        _0 = move (_1.0: i32);
-        return;
+        _0 = move (_1.0: i32);           // scope 0 at main.rs:5:5: 5:10
+        return;                          // scope 0 at main.rs:6:2: 6:2
     }
 }
 
 fn main() -> () {
-    let mut _0: ();
-    let _1: i32;
+    let mut _0: ();                      // return place in scope 0 at main.rs:8:11: 8:11
+    let _1: i32;                         // in scope 0 at main.rs:9:5: 9:10
 
     bb0: {
-        _1 = foo() -> [return: bb1, unwind continue];
+        _1 = foo() -> [return: bb1, unwind continue]; // scope 0 at main.rs:9:5: 9:10
+                                         // mir::Constant
+                                         // + span: main.rs:9:5: 9:8
+                                         // + literal: Const { ty: fn() -> i32 {foo}, val: Value(<ZST>) }
     }
 
     bb1: {
-        return;
+        return;                          // scope 0 at main.rs:10:2: 10:2
     }
 }