diff --git a/.babelrc.json b/.babelrc.json
index fafcc33869..a6bde80c55 100644
--- a/.babelrc.json
+++ b/.babelrc.json
@@ -1,9 +1,6 @@
 {
   "presets": [["@babel/preset-env", { "targets": { "node": "current" } }]],
-  "plugins": [
-    "./resources/inline-invariant",
-    "@babel/plugin-transform-flow-strip-types"
-  ],
+  "plugins": ["@babel/plugin-transform-flow-strip-types"],
   "overrides": [
     {
       "exclude": [
@@ -20,11 +17,15 @@
       ],
       "env": {
         "cjs": {
-          "presets": [["@babel/preset-env", { "modules": "commonjs" }]]
+          "presets": [["@babel/preset-env", { "modules": "commonjs" }]],
+          "plugins": ["./resources/inline-invariant"]
         },
         "mjs": {
           "presets": [["@babel/preset-env", { "modules": false }]],
-          "plugins": ["./resources/add-extension-to-import-paths"]
+          "plugins": [
+            "./resources/add-extension-to-import-paths",
+            "./resources/inline-invariant"
+          ]
         }
       }
     },
diff --git a/resources/inline-invariant.js b/resources/inline-invariant.js
index 682d24e276..9daed59862 100644
--- a/resources/inline-invariant.js
+++ b/resources/inline-invariant.js
@@ -21,7 +21,6 @@ module.exports = function inlineInvariant(context) {
     (%%cond%%) || devAssert(0, %%args%%)
   `);
 
-  const t = context.types;
   return {
     visitor: {
       CallExpression(path) {
@@ -40,13 +39,7 @@ module.exports = function inlineInvariant(context) {
         if (calleeName === 'invariant') {
           const [cond, args] = node.arguments;
 
-          // Check if it is unreachable invariant: "invariant(false, ...)"
-          if (cond.type === 'BooleanLiteral' && cond.value === false) {
-            addIstanbulIgnoreElse(path);
-          } else {
-            path.replaceWith(invariantTemplate({ cond, args }));
-          }
-          path.addComment('leading', ' istanbul ignore next ');
+          path.replaceWith(invariantTemplate({ cond, args }));
         } else if (calleeName === 'devAssert') {
           const [cond, args] = node.arguments;
           path.replaceWith(assertTemplate({ cond, args }));
@@ -54,17 +47,4 @@ module.exports = function inlineInvariant(context) {
       },
     },
   };
-
-  function addIstanbulIgnoreElse(path) {
-    const parentStatement = path.getStatementParent();
-    const previousStatement =
-      parentStatement.container[parentStatement.key - 1];
-    if (
-      previousStatement != null &&
-      previousStatement.type === 'IfStatement' &&
-      previousStatement.alternate == null
-    ) {
-      t.addComment(previousStatement, 'leading', ' istanbul ignore else ');
-    }
-  }
 };
diff --git a/src/__tests__/starWarsSchema.js b/src/__tests__/starWarsSchema.js
index 78a95647d3..6d3c778ba7 100644
--- a/src/__tests__/starWarsSchema.js
+++ b/src/__tests__/starWarsSchema.js
@@ -130,11 +130,12 @@ const characterInterface = new GraphQLInterfaceType({
     if (character.type === 'Human') {
       return humanType;
     }
+    // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
     if (character.type === 'Droid') {
       return droidType;
     }
 
-    // Not reachable. All possible types have been considered.
+    // istanbul ignore next (Not reachable. All possible types have been considered)
     invariant(false);
   },
 });
diff --git a/src/execution/__tests__/abstract-promise-test.js b/src/execution/__tests__/abstract-promise-test.js
index 6f58497225..0c79b54ff2 100644
--- a/src/execution/__tests__/abstract-promise-test.js
+++ b/src/execution/__tests__/abstract-promise-test.js
@@ -276,11 +276,12 @@ describe('Execute: Handles execution of abstract types with promises', () => {
         if (obj instanceof Cat) {
           return Promise.resolve(CatType);
         }
+        // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
         if (obj instanceof Human) {
           return Promise.resolve(HumanType);
         }
 
-        // Not reachable. All possible types have been considered.
+        // istanbul ignore next (Not reachable. All possible types have been considered)
         invariant(false);
       },
       fields: {
@@ -405,11 +406,12 @@ describe('Execute: Handles execution of abstract types with promises', () => {
         if (obj instanceof Cat) {
           return Promise.resolve(CatType);
         }
+        // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
         if (obj instanceof Human) {
           return Promise.resolve(HumanType);
         }
 
-        // Not reachable. All possible types have been considered.
+        // istanbul ignore next (Not reachable. All possible types have been considered)
         invariant(false);
       },
       types: [DogType, CatType],
@@ -481,11 +483,12 @@ describe('Execute: Handles execution of abstract types with promises', () => {
         if (obj instanceof Dog) {
           return Promise.resolve('Dog');
         }
+        // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
         if (obj instanceof Cat) {
           return Promise.resolve('Cat');
         }
 
-        // Not reachable. All possible types have been considered.
+        // istanbul ignore next (Not reachable. All possible types have been considered)
         invariant(false);
       },
       fields: {
diff --git a/src/execution/__tests__/abstract-test.js b/src/execution/__tests__/abstract-test.js
index 10b07c6d6b..3e42ead8b5 100644
--- a/src/execution/__tests__/abstract-test.js
+++ b/src/execution/__tests__/abstract-test.js
@@ -199,11 +199,12 @@ describe('Execute: Handles execution of abstract types', () => {
         if (obj instanceof Cat) {
           return CatType;
         }
+        // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
         if (obj instanceof Human) {
           return HumanType;
         }
 
-        // Not reachable. All possible types have been considered.
+        // istanbul ignore next (Not reachable. All possible types have been considered)
         invariant(false);
       },
       fields: {
@@ -329,11 +330,12 @@ describe('Execute: Handles execution of abstract types', () => {
         if (obj instanceof Cat) {
           return CatType;
         }
+        // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
         if (obj instanceof Human) {
           return HumanType;
         }
 
-        // Not reachable. All possible types have been considered.
+        // istanbul ignore next (Not reachable. All possible types have been considered)
         invariant(false);
       },
       types: [DogType, CatType],
@@ -490,11 +492,12 @@ describe('Execute: Handles execution of abstract types', () => {
         if (obj instanceof Dog) {
           return 'Dog';
         }
+        // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
         if (obj instanceof Cat) {
           return 'Cat';
         }
 
-        // Not reachable. All possible types have been considered.
+        // istanbul ignore next (Not reachable. All possible types have been considered)
         invariant(false);
       },
       fields: {
diff --git a/src/execution/__tests__/union-interface-test.js b/src/execution/__tests__/union-interface-test.js
index 39e2518a4f..602385edaf 100644
--- a/src/execution/__tests__/union-interface-test.js
+++ b/src/execution/__tests__/union-interface-test.js
@@ -119,11 +119,12 @@ const PetType = new GraphQLUnionType({
     if (value instanceof Dog) {
       return DogType;
     }
+    // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
     if (value instanceof Cat) {
       return CatType;
     }
 
-    // Not reachable. All possible types have been considered.
+    // istanbul ignore next (Not reachable. All possible types have been considered)
     invariant(false);
   },
 });
diff --git a/src/execution/execute.js b/src/execution/execute.js
index 084ea46ba5..821b6e403f 100644
--- a/src/execution/execute.js
+++ b/src/execution/execute.js
@@ -868,6 +868,7 @@ function completeValue(
   }
 
   // If field type is Object, execute and complete all sub-selections.
+  // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
   if (isObjectType(returnType)) {
     return completeObjectValue(
       exeContext,
@@ -879,7 +880,7 @@ function completeValue(
     );
   }
 
-  // Not reachable. All possible output types have been considered.
+  // istanbul ignore next (Not reachable. All possible output types have been considered)
   invariant(
     false,
     'Cannot complete value of unexpected output type: ' +
diff --git a/src/type/introspection.js b/src/type/introspection.js
index 6ef4b0137c..12d833cf11 100644
--- a/src/type/introspection.js
+++ b/src/type/introspection.js
@@ -222,11 +222,12 @@ export const __Type = new GraphQLObjectType({
           if (isListType(type)) {
             return TypeKind.LIST;
           }
+          // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
           if (isNonNullType(type)) {
             return TypeKind.NON_NULL;
           }
 
-          // Not reachable. All possible types have been considered.
+          // istanbul ignore next (Not reachable. All possible types have been considered)
           invariant(false, `Unexpected type: "${inspect((type: empty))}".`);
         },
       },
diff --git a/src/utilities/astFromValue.js b/src/utilities/astFromValue.js
index d4ea450624..4756225085 100644
--- a/src/utilities/astFromValue.js
+++ b/src/utilities/astFromValue.js
@@ -101,6 +101,7 @@ export function astFromValue(value: mixed, type: GraphQLInputType): ?ValueNode {
     return { kind: Kind.OBJECT, fields: fieldNodes };
   }
 
+  // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
   if (isLeafType(type)) {
     // Since value is an internally represented value, it must be serialized
     // to an externally represented value before converting into an AST.
@@ -142,7 +143,7 @@ export function astFromValue(value: mixed, type: GraphQLInputType): ?ValueNode {
     throw new TypeError(`Cannot convert value to AST: ${inspect(serialized)}.`);
   }
 
-  // Not reachable. All possible input types have been considered.
+  // istanbul ignore next (Not reachable. All possible input types have been considered)
   invariant(false, 'Unexpected input type: ' + inspect((type: empty)));
 }
 
diff --git a/src/utilities/coerceInputValue.js b/src/utilities/coerceInputValue.js
index b116d514c2..865c16769c 100644
--- a/src/utilities/coerceInputValue.js
+++ b/src/utilities/coerceInputValue.js
@@ -148,6 +148,7 @@ function coerceInputValueImpl(
     return coercedValue;
   }
 
+  // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
   if (isLeafType(type)) {
     let parseResult;
 
@@ -185,6 +186,6 @@ function coerceInputValueImpl(
     return parseResult;
   }
 
-  // Not reachable. All possible input types have been considered.
+  // istanbul ignore next (Not reachable. All possible input types have been considered)
   invariant(false, 'Unexpected input type: ' + inspect((type: empty)));
 }
diff --git a/src/utilities/extendSchema.js b/src/utilities/extendSchema.js
index 9de5c74ea3..6142bf360e 100644
--- a/src/utilities/extendSchema.js
+++ b/src/utilities/extendSchema.js
@@ -282,11 +282,12 @@ export function extendSchemaImpl(
     if (isEnumType(type)) {
       return extendEnumType(type);
     }
+    // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
     if (isInputObjectType(type)) {
       return extendInputObjectType(type);
     }
 
-    // Not reachable. All possible types have been considered.
+    // istanbul ignore next (Not reachable. All possible types have been considered)
     invariant(false, 'Unexpected type: ' + inspect((type: empty)));
   }
 
@@ -686,7 +687,7 @@ export function extendSchemaImpl(
       }
     }
 
-    // Not reachable. All possible type definition nodes have been considered.
+    // istanbul ignore next (Not reachable. All possible type definition nodes have been considered)
     invariant(
       false,
       'Unexpected type definition node: ' + inspect((astNode: empty)),
diff --git a/src/utilities/findBreakingChanges.js b/src/utilities/findBreakingChanges.js
index b3dc7f5eb0..3eeca5089b 100644
--- a/src/utilities/findBreakingChanges.js
+++ b/src/utilities/findBreakingChanges.js
@@ -526,11 +526,12 @@ function typeKindName(type: GraphQLNamedType): string {
   if (isEnumType(type)) {
     return 'an Enum type';
   }
+  // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
   if (isInputObjectType(type)) {
     return 'an Input type';
   }
 
-  // Not reachable. All possible named types have been considered.
+  // istanbul ignore next (Not reachable. All possible named types have been considered)
   invariant(false, 'Unexpected type: ' + inspect((type: empty)));
 }
 
diff --git a/src/utilities/lexicographicSortSchema.js b/src/utilities/lexicographicSortSchema.js
index 494fc5adfc..0ef144a694 100644
--- a/src/utilities/lexicographicSortSchema.js
+++ b/src/utilities/lexicographicSortSchema.js
@@ -137,6 +137,7 @@ export function lexicographicSortSchema(schema: GraphQLSchema): GraphQLSchema {
         values: sortObjMap(config.values),
       });
     }
+    // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
     if (isInputObjectType(type)) {
       const config = type.toConfig();
       return new GraphQLInputObjectType({
@@ -145,7 +146,7 @@ export function lexicographicSortSchema(schema: GraphQLSchema): GraphQLSchema {
       });
     }
 
-    // Not reachable. All possible types have been considered.
+    // istanbul ignore next (Not reachable. All possible types have been considered)
     invariant(false, 'Unexpected type: ' + inspect((type: empty)));
   }
 }
diff --git a/src/utilities/printSchema.js b/src/utilities/printSchema.js
index e856abfea5..1f86f22332 100644
--- a/src/utilities/printSchema.js
+++ b/src/utilities/printSchema.js
@@ -172,11 +172,12 @@ export function printType(type: GraphQLNamedType, options?: Options): string {
   if (isEnumType(type)) {
     return printEnum(type, options);
   }
+  // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
   if (isInputObjectType(type)) {
     return printInputObject(type, options);
   }
 
-  // Not reachable. All possible types have been considered.
+  // istanbul ignore next (Not reachable. All possible types have been considered)
   invariant(false, 'Unexpected type: ' + inspect((type: empty)));
 }
 
diff --git a/src/utilities/typeFromAST.js b/src/utilities/typeFromAST.js
index c418511dae..9018682b9e 100644
--- a/src/utilities/typeFromAST.js
+++ b/src/utilities/typeFromAST.js
@@ -48,10 +48,11 @@ export function typeFromAST(schema, typeNode) {
     innerType = typeFromAST(schema, typeNode.type);
     return innerType && GraphQLNonNull(innerType);
   }
+  // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
   if (typeNode.kind === Kind.NAMED_TYPE) {
     return schema.getType(typeNode.name.value);
   }
 
-  // Not reachable. All possible type nodes have been considered.
+  // istanbul ignore next (Not reachable. All possible type nodes have been considered)
   invariant(false, 'Unexpected type node: ' + inspect((typeNode: empty)));
 }
diff --git a/src/utilities/valueFromAST.js b/src/utilities/valueFromAST.js
index 4820b57c46..9b5efce077 100644
--- a/src/utilities/valueFromAST.js
+++ b/src/utilities/valueFromAST.js
@@ -131,6 +131,7 @@ export function valueFromAST(
     return coercedObj;
   }
 
+  // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
   if (isLeafType(type)) {
     // Scalars and Enums fulfill parsing a literal value via parseLiteral().
     // Invalid values represent a failure to parse correctly, in which case
@@ -147,7 +148,7 @@ export function valueFromAST(
     return result;
   }
 
-  // Not reachable. All possible input types have been considered.
+  // istanbul ignore next (Not reachable. All possible input types have been considered)
   invariant(false, 'Unexpected input type: ' + inspect((type: empty)));
 }
 
diff --git a/src/utilities/valueFromASTUntyped.js b/src/utilities/valueFromASTUntyped.js
index 5ccfef9e7d..a879d460ac 100644
--- a/src/utilities/valueFromASTUntyped.js
+++ b/src/utilities/valueFromASTUntyped.js
@@ -53,6 +53,6 @@ export function valueFromASTUntyped(
       return variables?.[valueNode.name.value];
   }
 
-  // Not reachable. All possible value nodes have been considered.
+  // istanbul ignore next (Not reachable. All possible value nodes have been considered)
   invariant(false, 'Unexpected value node: ' + inspect((valueNode: empty)));
 }
diff --git a/src/validation/rules/KnownDirectivesRule.js b/src/validation/rules/KnownDirectivesRule.js
index 9bece5bfce..61fd54f234 100644
--- a/src/validation/rules/KnownDirectivesRule.js
+++ b/src/validation/rules/KnownDirectivesRule.js
@@ -134,6 +134,6 @@ function getDirectiveLocationForOperation(
       return DirectiveLocation.SUBSCRIPTION;
   }
 
-  // Not reachable. All possible types have been considered.
+  // istanbul ignore next (Not reachable. All possible types have been considered)
   invariant(false, 'Unexpected operation: ' + inspect((operation: empty)));
 }
diff --git a/src/validation/rules/PossibleTypeExtensionsRule.js b/src/validation/rules/PossibleTypeExtensionsRule.js
index 1d0db909e9..3e7044dd5e 100644
--- a/src/validation/rules/PossibleTypeExtensionsRule.js
+++ b/src/validation/rules/PossibleTypeExtensionsRule.js
@@ -113,11 +113,12 @@ function typeToExtKind(type) {
   if (isEnumType(type)) {
     return Kind.ENUM_TYPE_EXTENSION;
   }
+  // istanbul ignore else (See: 'https://github.com/graphql/graphql-js/issues/2618')
   if (isInputObjectType(type)) {
     return Kind.INPUT_OBJECT_TYPE_EXTENSION;
   }
 
-  // Not reachable. All possible types have been considered.
+  // istanbul ignore next (Not reachable. All possible types have been considered)
   invariant(false, 'Unexpected type: ' + inspect((type: empty)));
 }
 
@@ -137,6 +138,6 @@ function extensionKindToTypeName(kind) {
       return 'input object';
   }
 
-  // Not reachable. All possible types have been considered.
+  // istanbul ignore next (Not reachable. All possible types have been considered)
   invariant(false, 'Unexpected kind: ' + inspect(kind));
 }