diff --git a/internal/indexer/extractor_version.go b/internal/indexer/extractor_version.go
index 384c0852..d0d7d788 100644
--- a/internal/indexer/extractor_version.go
+++ b/internal/indexer/extractor_version.go
@@ -66,6 +66,7 @@ var extractorSaltExtLang = map[string]string{
 	".cxx":  "cpp",
 	".hpp":  "cpp",
 	".hh":   "cpp",
+	".hxx":  "cpp",
 	".cs":   "csharp",
 	// Razor templates are extracted by the C# extractor over their
 	// embedded code blocks, so a C# extraction fix has to re-flag them
diff --git a/internal/indexer/extractor_version_test.go b/internal/indexer/extractor_version_test.go
index 4300cbb8..023b56d8 100644
--- a/internal/indexer/extractor_version_test.go
+++ b/internal/indexer/extractor_version_test.go
@@ -70,12 +70,18 @@ func TestStaleLangsDetection(t *testing.T) {
 		if got := merkleSaltFor("src/Handler.php"); got != "php@2" {
 			t.Errorf("PHP extractor salt = %q, want php@2", got)
 		}
+		if got := merkleSaltFor("include/widget.hxx"); got != "cpp@2" {
+			t.Errorf("C++ extractor salt for .hxx = %q, want cpp@2", got)
+		}
 	})
 
 	t.Run("lang_for_file", func(t *testing.T) {
 		if got := ExtractorLangForFile("internal/auth/token.go"); got != "go" {
 			t.Errorf("ExtractorLangForFile(.go) = %q, want go", got)
 		}
+		if got := ExtractorLangForFile("include/widget.hxx"); got != "cpp" {
+			t.Errorf("ExtractorLangForFile(.hxx) = %q, want cpp", got)
+		}
 		if got := ExtractorLangForFile("README.zzz"); got != "" {
 			t.Errorf("ExtractorLangForFile(unknown) = %q, want \"\"", got)
 		}
diff --git a/internal/parser/languages/cpp.go b/internal/parser/languages/cpp.go
index d46006b5..e416aa85 100644
--- a/internal/parser/languages/cpp.go
+++ b/internal/parser/languages/cpp.go
@@ -118,7 +118,7 @@ func NewCppExtractor() *CppExtractor {
 }
 
 func (e *CppExtractor) Language() string     { return "cpp" }
-func (e *CppExtractor) Extensions() []string { return []string{".cpp", ".cc", ".cxx", ".hpp"} }
+func (e *CppExtractor) Extensions() []string { return []string{".cpp", ".cc", ".cxx", ".hpp", ".hxx"} }
 
 // --- Deferred call buffer ----------------------------------------
 
diff --git a/internal/parser/languages/cpp_test.go b/internal/parser/languages/cpp_test.go
index ad6ac82a..0cb745be 100644
--- a/internal/parser/languages/cpp_test.go
+++ b/internal/parser/languages/cpp_test.go
@@ -136,6 +136,7 @@ func TestCppExtractor_Extensions(t *testing.T) {
 	assert.Contains(t, exts, ".cc")
 	assert.Contains(t, exts, ".cxx")
 	assert.Contains(t, exts, ".hpp")
+	assert.Contains(t, exts, ".hxx")
 	assert.NotContains(t, exts, ".h")
 }