diff --git a/filelock/file_lock_test.go b/filelock/file_lock_test.go
index 3575fc2..6377a17 100644
--- a/filelock/file_lock_test.go
+++ b/filelock/file_lock_test.go
@@ -40,7 +40,7 @@ func TestLock(t *testing.T) {
 	// Avoid truncating an existing, non-empty file.
 	fi, err := os.Stat(filename)
 	if err == nil && fi.Size() != 0 {
-		t.Fatal("The file %s is not empty", filename)
+		t.Fatalf("The file %s is not empty", filename)
 	}
 
 	t.Logf("Locking %s\n", filename)
diff --git a/list2/list_test.go b/list2/list_test.go
index 3ab21fd..ddb0e2f 100644
--- a/list2/list_test.go
+++ b/list2/list_test.go
@@ -57,7 +57,7 @@ func checkListPointers(t *testing.T, l *List, es []*Element) {
 			Prev = prev
 		}
 		if p := e.prev; p != prev.index {
-			t.Errorf("elt[%d](%p).prev = %p, want %p", i, e, p, prev)
+			t.Errorf("elt[%d](%p).prev = %d, want %p", i, e, p, prev)
 		}
 		if p := e.Prev(); p != Prev {
 			t.Errorf("elt[%d](%p).Prev() = %p, want %p", i, e, p, Prev)
@@ -70,7 +70,7 @@ func checkListPointers(t *testing.T, l *List, es []*Element) {
 			Next = next
 		}
 		if n := e.next; n != next.index {
-			t.Errorf("elt[%d](%p).next = %p, want %p", i, e, n, next)
+			t.Errorf("elt[%d](%p).next = %d, want %p", i, e, n, next)
 		}
 		if n := e.Next(); n != Next {
 			t.Errorf("elt[%d](%p).Next() = %p, want %p", i, e, n, Next)