diff --git a/layer/layer_test.go b/layer/layer_test.go
index a0ecb53d22..b17c35c7bf 100644
--- a/layer/layer_test.go
+++ b/layer/layer_test.go
@@ -702,66 +702,3 @@ func TestRegisterExistingLayer(t *testing.T) {
 
 	assertReferences(t, layer2a, layer2b)
 }
-
-func graphDiffSize(ls Store, l Layer) (int64, error) {
-	cl := getCachedLayer(l)
-	var parent string
-	if cl.parent != nil {
-		parent = cl.parent.cacheID
-	}
-	return ls.(*layerStore).driver.DiffSize(cl.cacheID, parent)
-}
-
-func TestLayerSize(t *testing.T) {
-	ls, cleanup := newTestStore(t)
-	defer cleanup()
-
-	content1 := []byte("Base contents")
-	content2 := []byte("Added contents")
-
-	layer1, err := createLayer(ls, "", initWithFiles(newTestFile("file1", content1, 0644)))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	layer2, err := createLayer(ls, layer1.ChainID(), initWithFiles(newTestFile("file2", content2, 0644)))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	layer1DiffSize, err := graphDiffSize(ls, layer1)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if int(layer1DiffSize) != len(content1) {
-		t.Fatalf("Unexpected diff size %d, expected %d", layer1DiffSize, len(content1))
-	}
-
-	layer1Size, err := layer1.Size()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if expected := len(content1); int(layer1Size) != expected {
-		t.Fatalf("Unexpected size %d, expected %d", layer1Size, expected)
-	}
-
-	layer2DiffSize, err := graphDiffSize(ls, layer2)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if int(layer2DiffSize) != len(content2) {
-		t.Fatalf("Unexpected diff size %d, expected %d", layer2DiffSize, len(content2))
-	}
-
-	layer2Size, err := layer2.Size()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if expected := len(content1) + len(content2); int(layer2Size) != expected {
-		t.Fatalf("Unexpected size %d, expected %d", layer2Size, expected)
-	}
-}
diff --git a/layer/layer_unix_test.go b/layer/layer_unix_test.go
new file mode 100644
index 0000000000..75373411ea
--- /dev/null
+++ b/layer/layer_unix_test.go
@@ -0,0 +1,71 @@
+// +build !windows
+
+package layer
+
+import "testing"
+
+func graphDiffSize(ls Store, l Layer) (int64, error) {
+	cl := getCachedLayer(l)
+	var parent string
+	if cl.parent != nil {
+		parent = cl.parent.cacheID
+	}
+	return ls.(*layerStore).driver.DiffSize(cl.cacheID, parent)
+}
+
+// Unix as Windows graph driver does not support Changes which is indirectly
+// invoked by calling DiffSize on the driver
+func TestLayerSize(t *testing.T) {
+	ls, cleanup := newTestStore(t)
+	defer cleanup()
+
+	content1 := []byte("Base contents")
+	content2 := []byte("Added contents")
+
+	layer1, err := createLayer(ls, "", initWithFiles(newTestFile("file1", content1, 0644)))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	layer2, err := createLayer(ls, layer1.ChainID(), initWithFiles(newTestFile("file2", content2, 0644)))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	layer1DiffSize, err := graphDiffSize(ls, layer1)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if int(layer1DiffSize) != len(content1) {
+		t.Fatalf("Unexpected diff size %d, expected %d", layer1DiffSize, len(content1))
+	}
+
+	layer1Size, err := layer1.Size()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if expected := len(content1); int(layer1Size) != expected {
+		t.Fatalf("Unexpected size %d, expected %d", layer1Size, expected)
+	}
+
+	layer2DiffSize, err := graphDiffSize(ls, layer2)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if int(layer2DiffSize) != len(content2) {
+		t.Fatalf("Unexpected diff size %d, expected %d", layer2DiffSize, len(content2))
+	}
+
+	layer2Size, err := layer2.Size()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if expected := len(content1) + len(content2); int(layer2Size) != expected {
+		t.Fatalf("Unexpected size %d, expected %d", layer2Size, expected)
+	}
+
+}