diff --git a/libbb/fclose_nonstdin.c b/libbb/fclose_nonstdin.c
index 768ee94..6f3f373 100644
--- a/libbb/fclose_nonstdin.c
+++ b/libbb/fclose_nonstdin.c
@@ -14,7 +14,7 @@
 
 #include "libbb.h"
 
-int fclose_if_not_stdin(FILE *f)
+int FAST_FUNC fclose_if_not_stdin(FILE *f)
 {
 	/* Some more paranoid applets want ferror() check too */
 	int r = ferror(f); /* NB: does NOT set errno! */