diff --git a/src/ls.c b/src/ls.c
index 02534c259..08bc08f8c 100644
--- a/src/ls.c
+++ b/src/ls.c
@@ -138,6 +138,7 @@ struct bin_str
 #ifndef STDC_HEADERS
 time_t time ();
 void free ();
+char *malloc ();
 #endif
 
 void mode_string ();