diff --git a/lib/include/mat/config-default-cs4.h b/lib/include/mat/config-default-cs4.h
index 7aae9fc7e..71a79c10f 100644
--- a/lib/include/mat/config-default-cs4.h
+++ b/lib/include/mat/config-default-cs4.h
@@ -27,8 +27,16 @@
 /* #define HAVE_MAT_EVT_TRACEID     */
 #define HAVE_MAT_STORAGE
 #define HAVE_MAT_DEFAULT_HTTP_CLIENT
+// The two macros below are also added on the command line by
+// tests/{functests,unittests}/CMakeLists.txt when BUILD_LIVEEVENTINSPECTOR
+// / BUILD_PRIVACYGUARD are ON. Guard against -Wmacro-redefined under
+// -Werror on Linux/macOS.
+#ifndef HAVE_MAT_LIVEEVENTINSPECTOR
 #define HAVE_MAT_LIVEEVENTINSPECTOR
+#endif
+#ifndef HAVE_MAT_PRIVACYGUARD
 #define HAVE_MAT_PRIVACYGUARD
+#endif
 //#define HAVE_MAT_DEFAULT_FILTER
 #if defined(_WIN32) && !defined(_WINRT_DLL)
 #define HAVE_MAT_NETDETECT
diff --git a/lib/include/mat/config-default-exp.h b/lib/include/mat/config-default-exp.h
index 609692a01..256dfe615 100644
--- a/lib/include/mat/config-default-exp.h
+++ b/lib/include/mat/config-default-exp.h
@@ -25,8 +25,16 @@
 /* #define HAVE_MAT_EVT_TRACEID     */
 #define HAVE_MAT_STORAGE
 #define HAVE_MAT_DEFAULT_HTTP_CLIENT
+// The two macros below are also added on the command line by
+// tests/{functests,unittests}/CMakeLists.txt when BUILD_LIVEEVENTINSPECTOR
+// / BUILD_PRIVACYGUARD are ON. Guard against -Wmacro-redefined under
+// -Werror on Linux/macOS.
+#ifndef HAVE_MAT_LIVEEVENTINSPECTOR
 #define HAVE_MAT_LIVEEVENTINSPECTOR
+#endif
+#ifndef HAVE_MAT_PRIVACYGUARD
 #define HAVE_MAT_PRIVACYGUARD
+#endif
 //#define HAVE_MAT_DEFAULT_FILTER
 #if defined(_WIN32) && !defined(_WINRT_DLL)
 #define HAVE_MAT_NETDETECT
diff --git a/lib/include/mat/config-default.h b/lib/include/mat/config-default.h
index 9617611c9..2ddce7dfc 100644
--- a/lib/include/mat/config-default.h
+++ b/lib/include/mat/config-default.h
@@ -33,8 +33,16 @@
 /* #define HAVE_MAT_EVT_TRACEID     */
 #define HAVE_MAT_STORAGE
 #define HAVE_MAT_DEFAULT_HTTP_CLIENT
+// The two macros below are also added on the command line by
+// tests/{functests,unittests}/CMakeLists.txt when BUILD_LIVEEVENTINSPECTOR
+// / BUILD_PRIVACYGUARD are ON. Guard against -Wmacro-redefined under
+// -Werror on Linux/macOS.
+#ifndef HAVE_MAT_LIVEEVENTINSPECTOR
 #define HAVE_MAT_LIVEEVENTINSPECTOR
+#endif
+#ifndef HAVE_MAT_PRIVACYGUARD
 #define HAVE_MAT_PRIVACYGUARD
+#endif
 //#define HAVE_MAT_DEFAULT_FILTER
 #if defined(_WIN32) && !defined(_WINRT_DLL)
 #define HAVE_MAT_NETDETECT