diff --git a/src/tint/ast/enable.cc b/src/tint/ast/enable.cc
index acb669f8b2..a611cfbe19 100644
--- a/src/tint/ast/enable.cc
+++ b/src/tint/ast/enable.cc
@@ -34,7 +34,7 @@ Enable::ExtensionKind Enable::NameToKind(const std::string& name) {
         return Enable::ExtensionKind::kInternalExtensionForTesting;
     }
 
-    return Enable::ExtensionKind::kNotAnExtension;
+    return Enable::ExtensionKind::kNoExtension;
 }
 
 std::string Enable::KindToName(ExtensionKind kind) {
@@ -47,8 +47,8 @@ std::string Enable::KindToName(ExtensionKind kind) {
         // The reserved internal extension for testing
         case ExtensionKind::kInternalExtensionForTesting:
             return "InternalExtensionForTesting";
-        case ExtensionKind::kNotAnExtension:
-            // Return an empty string for kNotAnExtension
+        case ExtensionKind::kNoExtension:
+            // Return an empty string for kNoExtension
             return {};
             // No default case, as this switch must cover all ExtensionKind values.
     }
diff --git a/src/tint/ast/enable.h b/src/tint/ast/enable.h
index c5d1bdd653..69622e0033 100644
--- a/src/tint/ast/enable.h
+++ b/src/tint/ast/enable.h
@@ -32,6 +32,10 @@ class Enable : public Castable<Enable, Node> {
   public:
     ///  The enum class identifing each supported WGSL extension
     enum class ExtensionKind {
+        /// An internal reserved extension for test, named
+        /// "InternalExtensionForTesting".
+        kInternalExtensionForTesting,
+
         /// An extension for the experimental feature
         /// "chromium_experimental_dp4a".
         /// See crbug.com/tint/1497 for more details
@@ -39,28 +43,26 @@ class Enable : public Castable<Enable, Node> {
         /// A Chromium-specific extension for disabling uniformity analysis.
         kChromiumDisableUniformityAnalysis,
 
-        /// An internal reserved extension for test, named
-        /// "InternalExtensionForTesting"
-        kInternalExtensionForTesting = -2,
-        kNotAnExtension = -1,
+        /// Reserved for representing "No extension required" or "Not a valid extension".
+        kNoExtension,
     };
 
     /// Convert a string of extension name into one of ExtensionKind enum value,
-    /// the result will be ExtensionKind::kNotAnExtension if the name is not a
-    /// known extension name. A extension node of kind kNotAnExtension must not
+    /// the result will be ExtensionKind::kNoExtension if the name is not a
+    /// known extension name. A extension node of kind kNoExtension must not
     /// exist in the AST tree, and using a unknown extension name in WGSL code
     /// should result in a shader-creation error.
     /// @param name string of the extension name
     /// @return the ExtensionKind enum value for the extension of given name, or
-    /// kNotAnExtension if no known extension has the given name
+    /// kNoExtension if no known extension has the given name
     static ExtensionKind NameToKind(const std::string& name);
 
     /// Convert the ExtensionKind enum value to corresponding extension name
-    /// string. If the given enum value is kNotAnExtension or don't have a known
+    /// string. If the given enum value is kNoExtension or don't have a known
     /// name, return an empty string instead.
     /// @param kind the ExtensionKind enum value
     /// @return string of the extension name corresponding to the given kind, or
-    /// an empty string if the given enum value is kNotAnExtension or don't have a
+    /// an empty string if the given enum value is kNoExtension or don't have a
     /// known corresponding name
     static std::string KindToName(ExtensionKind kind);
 
diff --git a/src/tint/ast/enable_test.cc b/src/tint/ast/enable_test.cc
index 9fde780a5e..208c85df89 100644
--- a/src/tint/ast/enable_test.cc
+++ b/src/tint/ast/enable_test.cc
@@ -39,20 +39,20 @@ TEST_F(AstExtensionTest, Creation_InvalidName) {
     EXPECT_EQ(ext->source.range.begin.column, 2u);
     EXPECT_EQ(ext->source.range.end.line, 20u);
     EXPECT_EQ(ext->source.range.end.column, 5u);
-    EXPECT_EQ(ext->kind, ast::Enable::ExtensionKind::kNotAnExtension);
+    EXPECT_EQ(ext->kind, ast::Enable::ExtensionKind::kNoExtension);
 }
 
 TEST_F(AstExtensionTest, NameToKind_InvalidName) {
-    EXPECT_EQ(ast::Enable::NameToKind(std::string()), ast::Enable::ExtensionKind::kNotAnExtension);
+    EXPECT_EQ(ast::Enable::NameToKind(std::string()), ast::Enable::ExtensionKind::kNoExtension);
     EXPECT_EQ(ast::Enable::NameToKind("__ImpossibleExtensionName"),
-              ast::Enable::ExtensionKind::kNotAnExtension);
-    EXPECT_EQ(ast::Enable::NameToKind("123"), ast::Enable::ExtensionKind::kNotAnExtension);
+              ast::Enable::ExtensionKind::kNoExtension);
+    EXPECT_EQ(ast::Enable::NameToKind("123"), ast::Enable::ExtensionKind::kNoExtension);
 }
 
 TEST_F(AstExtensionTest, KindToName) {
     EXPECT_EQ(ast::Enable::KindToName(ast::Enable::ExtensionKind::kInternalExtensionForTesting),
               "InternalExtensionForTesting");
-    EXPECT_EQ(ast::Enable::KindToName(ast::Enable::ExtensionKind::kNotAnExtension), std::string());
+    EXPECT_EQ(ast::Enable::KindToName(ast::Enable::ExtensionKind::kNoExtension), std::string());
 }
 
 }  // namespace
diff --git a/src/tint/reader/wgsl/parser_impl.cc b/src/tint/reader/wgsl/parser_impl.cc
index c0ea04bc3b..e684790dcd 100644
--- a/src/tint/reader/wgsl/parser_impl.cc
+++ b/src/tint/reader/wgsl/parser_impl.cc
@@ -358,7 +358,7 @@ Maybe<bool> ParserImpl::enable_directive() {
             return Failure::kErrored;
         }
 
-        if (ast::Enable::NameToKind(name.value) != ast::Enable::ExtensionKind::kNotAnExtension) {
+        if (ast::Enable::NameToKind(name.value) != ast::Enable::ExtensionKind::kNoExtension) {
             const ast::Enable* extension = create<ast::Enable>(name.source, name.value);
             builder_.AST().AddEnable(extension);
         } else {
diff --git a/src/tint/resolver/validator.cc b/src/tint/resolver/validator.cc
index f9b0ba7c68..7a66ec4f61 100644
--- a/src/tint/resolver/validator.cc
+++ b/src/tint/resolver/validator.cc
@@ -1525,7 +1525,7 @@ bool Validator::RequiredExtensionForBuiltinFunction(const sem::Call* call,
     }
 
     const auto extension = builtin->RequiredExtension();
-    if (extension == ast::Enable::ExtensionKind::kNotAnExtension) {
+    if (extension == ast::Enable::ExtensionKind::kNoExtension) {
         return true;
     }
 
diff --git a/src/tint/sem/builtin.cc b/src/tint/sem/builtin.cc
index f102307c5c..faf451e01a 100644
--- a/src/tint/sem/builtin.cc
+++ b/src/tint/sem/builtin.cc
@@ -157,7 +157,7 @@ ast::Enable::ExtensionKind Builtin::RequiredExtension() const {
     if (IsDP4a()) {
         return ast::Enable::ExtensionKind::kChromiumExperimentalDP4a;
     }
-    return ast::Enable::ExtensionKind::kNotAnExtension;
+    return ast::Enable::ExtensionKind::kNoExtension;
 }
 
 }  // namespace tint::sem
diff --git a/src/tint/sem/builtin.h b/src/tint/sem/builtin.h
index 5d340ce461..4752f1608d 100644
--- a/src/tint/sem/builtin.h
+++ b/src/tint/sem/builtin.h
@@ -144,7 +144,7 @@ class Builtin final : public Castable<Builtin, CallTarget> {
     bool HasSideEffects() const;
 
     /// @returns the required extension of this builtin function. Returns
-    /// ast::Enable::ExtensionKind::kNotAnExtension if no extension is required.
+    /// ast::Enable::ExtensionKind::kNoExtension if no extension is required.
     ast::Enable::ExtensionKind RequiredExtension() const;
 
   private: