diff --git a/sys/src/libaml/aml.c b/sys/src/libaml/aml.c
index 0de0297a9..9d1298eb7 100644
--- a/sys/src/libaml/aml.c
+++ b/sys/src/libaml/aml.c
@@ -2062,7 +2062,7 @@ evalosi(void)
 	char *s;
 	int i;
 
-	s = deref(FP->arg[0]);
+	s = FP->env->arg[0];
 	if(s == nil || TAG(s) != 's')
 		return nil;
 	for(i = 0; i < nelem(w); i++)