diff --git a/scsh/cstuff.c b/scsh/cstuff.c
index 4d6620c..ccb9fd6 100644
--- a/scsh/cstuff.c
+++ b/scsh/cstuff.c
@@ -6,9 +6,10 @@ s48_value char_pp_2_string_list(char **vec){
 
     S48_DECLARE_GC_PROTECT(1);
     S48_GC_PROTECT_1(list);
-
-    while (*(++ptr)){
+    
+    while (ptr && *(ptr)){
       list = s48_cons (s48_enter_string (*ptr), list);
+      ptr++;
     }
     S48_GC_UNPROTECT();
     return list;