diff --git a/lib/curl_mem_undef.h b/lib/curl_mem_undef.h
index 1cfa43d9bc..2b0bef111d 100644
--- a/lib/curl_mem_undef.h
+++ b/lib/curl_mem_undef.h
@@ -47,7 +47,7 @@
 
 #undef fopen
 #ifdef CURL_FOPEN
-#define fopen(fname, mode)  CURL_FOPEN(fname, mode)
+#define fopen(fname, mode) CURL_FOPEN(fname, mode)
 #endif
 #undef fdopen
 #undef fclose