diff --git a/externals/zexy/src/strcmp.c b/externals/zexy/src/strcmp.c
index 362e917a5a202e3b9313cf4985cf0037227e2f62..6b85b6ce873f51831684a7f46b97fe35de030fed 100644
--- a/externals/zexy/src/strcmp.c
+++ b/externals/zexy/src/strcmp.c
@@ -80,7 +80,7 @@ static void list2binbuf(t_binbuf**bbuf, int *n, char**str, int argc,
   i=*n;
   s=*str;
 
-  if(' '==s[i]) {
+  if(s && ' '==s[i]) {
     s[i]=0;
   }
 }