diff --git a/src/emu/chan.c b/src/emu/chan.c
index fccfe7c..8ab9ef3 100644
--- a/src/emu/chan.c
+++ b/src/emu/chan.c
@@ -179,8 +179,10 @@ chan_pop(struct chan *chan, struct value evalue)
 	struct value *value = &stack->values[stack->n - 1];
 
 	if (!value_is_equal(value, &evalue)) {
-		err("%s: unexpected value %ld (expected %ld)",
-				chan->name, value->i, evalue.i);
+		err("%s: unexpected value %s (expected %s)",
+				chan->name,
+				value_str(*value),
+				value_str(evalue));
 		return -1;
 	}