diff --git a/pkg/clustermanager/cluster_creator_test.go b/pkg/clustermanager/cluster_creator_test.go
index 9c049926a5ea9..8a16344584da2 100644
--- a/pkg/clustermanager/cluster_creator_test.go
+++ b/pkg/clustermanager/cluster_creator_test.go
@@ -65,7 +65,7 @@ func TestClusterCreatorCreateSync(t *testing.T) {
 	clusCreator, tt := newClusterCreator(t)
 	clusterName := tt.spec.Cluster.Name
 	path := "testpath"
-	writer := os.NewFile(uintptr(*pointer.Uint(1)), "test")
+	writer := os.NewFile(uintptr(*pointer.Uint(0)), "test")
 	tt.expectApplierRun(tt.ctx, tt.spec, *tt.mgmtCluster)
 	tt.expectWriteKubeconfig(tt.ctx, clusterName, tt.mgmtCluster.KubeconfigFile, writer)
 	tt.expectFileCreate(clusterName, path, writer)
diff --git a/pkg/kubeconfig/kubeconfig_writer_test.go b/pkg/kubeconfig/kubeconfig_writer_test.go
index 67a700d2f4137..8c7f727a3328b 100644
--- a/pkg/kubeconfig/kubeconfig_writer_test.go
+++ b/pkg/kubeconfig/kubeconfig_writer_test.go
@@ -86,7 +86,7 @@ func TestWriteKubeconfig(t *testing.T) {
 	}
 	for _, tc := range tests {
 		writer, tt := newKubeconfigWriter(t)
-		buf := bytes.NewBuffer([]byte{})
+		buf := bytes.NewBuffer(make([]byte, tc.secret.Size()))
 		tt.buildClient(tc.buildErr, tc.secret)
 		err := writer.WriteKubeconfig(tt.ctx, tc.clusterName, tt.mgmtCluster.KubeconfigFile, buf)
 		if !tc.expectErr {