diff --git a/src/os_unix.c b/src/os_unix.c
index 9012974..5d52a7f 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3602,7 +3602,7 @@
 		*p++ = NUL;
 	    p = skipwhite(p);
 	}
-	if (i == 0)
+	if (argv == NULL)
 	{
 	    argv = (char **)alloc((unsigned)((argc + 4) * sizeof(char *)));
 	    if (argv == NULL)	    /* out of memory */