diff --git a/maps/hashmap/hashmap_test.go b/maps/hashmap/hashmap_test.go
index 46ffc0f..31c026b 100644
--- a/maps/hashmap/hashmap_test.go
+++ b/maps/hashmap/hashmap_test.go
@@ -129,12 +129,12 @@ func TestHashMap(t *testing.T) {
 	m.Remove(2)
 
 	// Test Keys()
-	if actualValue, expactedValue := fmt.Sprintf("", m.Keys()...), ""; actualValue != expactedValue {
+	if actualValue, expactedValue := fmt.Sprintf("%s", m.Keys()), "[]"; actualValue != expactedValue {
 		t.Errorf("Got %v expected %v", actualValue, expactedValue)
 	}
 
 	// test Values()
-	if actualValue, expactedValue := fmt.Sprintf("", m.Values()...), ""; actualValue != expactedValue {
+	if actualValue, expactedValue := fmt.Sprintf("%s", m.Values()), "[]"; actualValue != expactedValue {
 		t.Errorf("Got %v expected %v", actualValue, expactedValue)
 	}
 
diff --git a/maps/treemap/treemap_test.go b/maps/treemap/treemap_test.go
index 314a052..03fb23c 100644
--- a/maps/treemap/treemap_test.go
+++ b/maps/treemap/treemap_test.go
@@ -130,12 +130,12 @@ func TestTreeMap(t *testing.T) {
 	m.Remove(2)
 
 	// Test Keys()
-	if actualValue, expactedValue := fmt.Sprintf("", m.Keys()...), ""; actualValue != expactedValue {
+	if actualValue, expactedValue := fmt.Sprintf("%s", m.Keys()), "[]"; actualValue != expactedValue {
 		t.Errorf("Got %v expected %v", actualValue, expactedValue)
 	}
 
 	// test Values()
-	if actualValue, expactedValue := fmt.Sprintf("", m.Values()...), ""; actualValue != expactedValue {
+	if actualValue, expactedValue := fmt.Sprintf("%s", m.Values()), "[]"; actualValue != expactedValue {
 		t.Errorf("Got %v expected %v", actualValue, expactedValue)
 	}
 
diff --git a/trees/redblacktree/redblacktree_test.go b/trees/redblacktree/redblacktree_test.go
index b3ae6f3..58fe60f 100644
--- a/trees/redblacktree/redblacktree_test.go
+++ b/trees/redblacktree/redblacktree_test.go
@@ -130,12 +130,12 @@ func TestRedBlackTree(t *testing.T) {
 	tree.Remove(2)
 
 	// Test Keys()
-	if actualValue, expactedValue := fmt.Sprintf("", tree.Keys()...), ""; actualValue != expactedValue {
+	if actualValue, expactedValue := fmt.Sprintf("%s", tree.Keys()), "[]"; actualValue != expactedValue {
 		t.Errorf("Got %v expected %v", actualValue, expactedValue)
 	}
 
 	// test Values()
-	if actualValue, expactedValue := fmt.Sprintf("", tree.Values()...), ""; actualValue != expactedValue {
+	if actualValue, expactedValue := fmt.Sprintf("%s", tree.Values()), "[]"; actualValue != expactedValue {
 		t.Errorf("Got %v expected %v", actualValue, expactedValue)
 	}