diff --git a/lib/codeintel/languages/extensions.go b/lib/codeintel/languages/extensions.go
index 2d0c536bbf3..d222f456bb4 100644
--- a/lib/codeintel/languages/extensions.go
+++ b/lib/codeintel/languages/extensions.go
@@ -41,8 +41,8 @@ func GetLanguageByNameOrAlias(nameOrAlias string) (lang string, ok bool) {
 // Mutually consistent with getLanguagesByExtension, see the tests
 // for the exact invariants.
 func GetLanguageExtensions(language string) []string {
-	if lang, ok := unsupportedByEnryNameToExtensionMap[language]; ok {
-		return []string{lang}
+	if langs, ok := unsupportedByEnryNameToExtensionMap[language]; ok {
+		return langs
 	}
 
 	ignoreExts, isNiche := nicheExtensionUsages[language]
@@ -114,6 +114,13 @@ var overrideAmbiguousExtensionsMap = map[string]string{
 }
 
 var unsupportedByEnryExtensionToNameMap = map[string]string{
+	// Extensions for the Apex programming language
+	// See https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_dev_guide.htm
+	".apex":    "Apex",
+	".apxt":    "Apex",
+	".apxc":    "Apex",
+	".cls":     "Apex",
+	".trigger": "Apex",
 	// See TODO(id: remove-pkl-special-case)
 	".pkl":   "Pkl",
 	".magik": "Magik",
@@ -171,10 +178,10 @@ var unsupportedByEnryAliasMap = func() map[string]string {
 	return out
 }()
 
-func reverseMap(m map[string]string) map[string]string {
-	n := make(map[string]string, len(m))
+func reverseMap(m map[string]string) map[string][]string {
+	n := make(map[string][]string, len(m))
 	for k, v := range m {
-		n[v] = k
+		n[v] = append(n[v], k)
 	}
 	return n
 }
diff --git a/lib/codeintel/languages/extensions_test.go b/lib/codeintel/languages/extensions_test.go
index 12557122310..645765c3cce 100644
--- a/lib/codeintel/languages/extensions_test.go
+++ b/lib/codeintel/languages/extensions_test.go
@@ -12,7 +12,12 @@ import (
 
 // Languages/extensions that we don't want to regress
 var nonAmbiguousExtensionsCheck = map[string]string{
-	".js": "JavaScript",
+	".apex":    "Apex",
+	".apxt":    "Apex",
+	".apxc":    "Apex",
+	".cls":     "Apex",
+	".trigger": "Apex",
+	".js":      "JavaScript",
 	// Linguist removed JSX (but not TSX) as a separate language:
 	// https://github.com/github-linguist/linguist/pull/5133
 	".jsx":   "JavaScript",
@@ -60,19 +65,23 @@ func TestGetLanguageByAlias_NonAmbiguousLanguages(t *testing.T) {
 }
 
 func TestGetLanguageExtensions_UnsupportedExtensions(t *testing.T) {
-	for language, ext := range unsupportedByEnryNameToExtensionMap {
+	for language, exts := range unsupportedByEnryNameToExtensionMap {
 		extensions := GetLanguageExtensions(language)
-		require.Contains(t, extensions, ext,
-			"maybe a typo in `unsupportedByEnryNameToExtensionMap`?")
+		for _, ext := range exts {
+			require.Contains(t, extensions, ext,
+				"maybe a typo in `unsupportedByEnryNameToExtensionMap`?")
+		}
 	}
 }
 
 func TestGetLanguageExtensions_NonAmbiguousExtensions(t *testing.T) {
 	langMap := reverseMap(nonAmbiguousExtensionsCheck)
-	for language, ext := range langMap {
+	for language, exts := range langMap {
 		extensions := GetLanguageExtensions(language)
-		require.Contains(t, extensions, ext,
-			"If this test fails when updating enry, maybe `overrideAmbiguousExtensionsMap` needs updating")
+		for _, ext := range exts {
+			require.Contains(t, extensions, ext,
+				"If this test fails when updating enry, maybe `overrideAmbiguousExtensionsMap` needs updating")
+		}
 	}
 }
 
@@ -169,15 +178,30 @@ func TestExtensionsConsistency2(t *testing.T) {
 // cases for Pkl.
 func TestUnsupportedByEnry(t *testing.T) {
 	for lang := range unsupportedByEnryNameToExtensionMap {
-		_, found := enrydata.ExtensionsByLanguage[lang]
-		require.False(t, found, "looks like language %q is supported by enry; remove it from unsupportedByEnryNameToExtensionMap")
+		enry_extensions, found := enrydata.ExtensionsByLanguage[lang]
+		if found {
+			validateLanguageAgainstGoEnry(t, "unsupportedByEnryNameToExtensionMap", enry_extensions, lang)
+		}
 	}
 	for _, lang := range unsupportedByEnryAliasMap {
-		_, found := enrydata.ExtensionsByLanguage[lang]
-		require.False(t, found, "looks like language %q is supported by enry; remove it from unsupportedByEnryAliasMap")
+		enry_extensions, found := enrydata.ExtensionsByLanguage[lang]
+		if found {
+			validateLanguageAgainstGoEnry(t, "unsupportedByEnryAliasMap", enry_extensions, lang)
+		}
 	}
 	for _, lang := range unsupportedByEnryExtensionToNameMap {
-		_, found := enrydata.ExtensionsByLanguage[lang]
-		require.False(t, found, "looks like language %q is supported by enry; remove it from unsupportedByEnryExtensionToNameMap")
+		enry_extensions, found := enrydata.ExtensionsByLanguage[lang]
+		if found {
+			validateLanguageAgainstGoEnry(t, "unsupportedByEnryExtensionToNameMap", enry_extensions, lang)
+		}
 	}
 }
+
+func validateLanguageAgainstGoEnry(t *testing.T, name string, enryExtensions []string, lang string) {
+	enryExtensions = slices.Clone(enryExtensions)
+	slices.Sort(enryExtensions)
+	sgExtensions := slices.Clone(unsupportedByEnryNameToExtensionMap[lang])
+	slices.Sort(sgExtensions)
+
+	require.NotEqualf(t, enryExtensions, sgExtensions, "looks like language %q is supported by enry with the same extensions; remove it from %q", lang, name)
+}