diff --git a/lang/cem/libcc/gen/getenv.c b/lang/cem/libcc/gen/getenv.c
index 360be4d5e..8c273561f 100644
--- a/lang/cem/libcc/gen/getenv.c
+++ b/lang/cem/libcc/gen/getenv.c
@@ -5,6 +5,7 @@ register char *name;
   extern char **environ;
   register char **v = environ, *p, *q;
 
+  if (v == 0 || name == 0) return 0;
   while ((p = *v++) != 0) {
 	q = name;
 	while (*q && *q++ == *p++) /* nothing */ ;