diff --git a/pass/cfg.go b/pass/cfg.go
index 198208d..d8e8fd4 100644
--- a/pass/cfg.go
+++ b/pass/cfg.go
@@ -17,7 +17,7 @@ func LabelTarget(fn *ir.Function) error {
 		switch n := node.(type) {
 		case ir.Label:
 			if pending != empty {
-				return errors.New("instruction should follow a label")
+				return fmt.Errorf("expected instruction following label %q", pending)
 			}
 			pending = n
 			if _, found := target[pending]; found {
diff --git a/pass/cfg_test.go b/pass/cfg_test.go
index 42f1004..5dc8857 100644
--- a/pass/cfg_test.go
+++ b/pass/cfg_test.go
@@ -66,7 +66,7 @@ func TestLabelTargetInstructionFollowLabel(t *testing.T) {
 
 	err := LabelTarget(f)
 
-	if err == nil || err.Error() != "instruction should follow a label" {
+	if err == nil || err.Error() != "expected instruction following label \"lblA\"" {
 		t.Fatalf("expected error when label is not followed by instruction; got %v", err)
 	}
 }