--- a/src/bz-inspector.c
+++ b/src/bz-inspector.c
@@ -18,6 +18,9 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
+#define _GNU_SOURCE
+#include <string.h>
+
 #include "bz-inspector.h"
 #include "bz-entry-inspector.h"
 
--- a/src/bz-search-engine.c
+++ b/src/bz-search-engine.c
@@ -18,6 +18,9 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
+#define _GNU_SOURCE
+#include <string.h>
+
 #include "bz-search-engine.h"
 #include "bz-entry-group.h"
 #include "bz-env.h"
--- a/src/bz-installed-page.c
+++ b/src/bz-installed-page.c
@@ -18,6 +18,9 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
+#define _GNU_SOURCE
+#include <string.h>
+
 #include <glib/gi18n.h>
 
 #include "bz-entry-group-util.h"