diff --git a/cc/compdb.go b/cc/compdb.go
index 1102651..ecc67b8 100644
--- a/cc/compdb.go
+++ b/cc/compdb.go
@@ -141,7 +141,7 @@
 		isAsm = false
 		isCpp = false
 		clangPath = ccPath
-	case ".cpp", ".cc", ".mm":
+	case ".cpp", ".cc", ".cxx", ".mm":
 		isAsm = false
 		isCpp = true
 		clangPath = cxxPath