diff --git a/libcpp/mkdeps.c b/libcpp/mkdeps.c
index 471e449a19d..1867e0089d7 100644
--- a/libcpp/mkdeps.c
+++ b/libcpp/mkdeps.c
@@ -162,7 +162,6 @@ munge (const char *str, const char *trail = nullptr)
 	      /* FALLTHROUGH  */
 
 	    case '#':
-	    case ':':
 	      buf[dst++] = '\\';
 	      /* FALLTHROUGH  */