diff --git a/sc2/src/regex/regex.c b/sc2/src/regex/regex.c
index 7a4f304cd..45d4a360c 100644
--- a/sc2/src/regex/regex.c
+++ b/sc2/src/regex/regex.c
@@ -83,9 +83,9 @@
 #include <regex.h>
 #include "regex_internal.h"
 
-#include "regex_internal.c"
-#include "regcomp.c"
-#include "regexec.c"
+#include "regex_internal.ci"
+#include "regcomp.ci"
+#include "regexec.ci"
 
 /* Binary backward compatibility.  */
 #if _LIBC