diff --git a/Tests/mocks/systimerifc/itimermsg.h b/Tests/mocks/systimerifc/itimermsg.h
new file mode 100644
index 0000000..32f0e23
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+++ b/Tests/mocks/systimerifc/itimermsg.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2023 Comcast Cable Communications Management, LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * Stub header for systimerifc/itimermsg.h
+ * Required when ENABLE_SYSTIMEMGR_SUPPORT is defined in test builds
+ * where the real systimemgr package is not installed.
+ */
+#pragma once
+
+#ifndef IARM_BUS_SYSTIME_MGR_NAME
+#define IARM_BUS_SYSTIME_MGR_NAME    "SYSTEMTIME"
+#endif
+
+#ifndef TIMER_STATUS_MSG
+#define TIMER_STATUS_MSG             "TimerStatus"
+#endif
+
+#ifndef cTIMER_STATUS_UPDATE
+#define cTIMER_STATUS_UPDATE         0
+#endif
+
+#ifndef cTIMER_STATUS_MESSAGE_LENGTH
+#define cTIMER_STATUS_MESSAGE_LENGTH 256
+#endif
+
+typedef struct {
+    char message[cTIMER_STATUS_MESSAGE_LENGTH];
+    char timerSrc[cTIMER_STATUS_MESSAGE_LENGTH];
+    char currentTime[cTIMER_STATUS_MESSAGE_LENGTH];
+} TimerMsg;