diff --git a/roaring/roaring_helpers_test.go b/roaring/roaring_helpers_test.go
index 1fa3d82f9..073983a7f 100644
--- a/roaring/roaring_helpers_test.go
+++ b/roaring/roaring_helpers_test.go
@@ -255,8 +255,7 @@ func doContainer(typ byte, data interface{}) *Container {
 	case containerArray:
 		return NewContainerArray(data.([]uint16)).Freeze()
 	case containerBitmap:
-		c := NewContainerBitmap(-1, data.([]uint64)).Freeze()
-		return c
+		return NewContainerBitmap(-1, data.([]uint64)).Freeze()
 	case containerRun:
 		return NewContainerRun(data.([]interval16)).Freeze()
 	}
diff --git a/roaring/roaring_internal_test.go b/roaring/roaring_internal_test.go
index 085b6e1d1..4cf0b48d6 100644
--- a/roaring/roaring_internal_test.go
+++ b/roaring/roaring_internal_test.go
@@ -4391,8 +4391,8 @@ func TestUnionRunRunInPlaceBitwiseCompare(t *testing.T) {
 	for _, a := range runs {
 		for _, b := range runs {
 			t.Run(a.name+"-"+b.name, func(t *testing.T) {
-				arun := doContainer(containerRun, a.run)
-				brun := doContainer(containerRun, b.run)
+				arun := doContainer(containerRun, a.run).Thaw()
+				brun := doContainer(containerRun, b.run).Thaw()
 
 				out1 := unionBitmapRunInPlace(arun.runToBitmap(), brun)
 				out2 := unionRunRunInPlace(arun, brun)