diff --git a/bin/tests/master_test.c b/bin/tests/master_test.c
index ca99f36711..4910f8f582 100644
--- a/bin/tests/master_test.c
+++ b/bin/tests/master_test.c
@@ -19,6 +19,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include <isc/mem.h>
 #include <isc/buffer.h>
diff --git a/bin/tests/shutdown_test.c b/bin/tests/shutdown_test.c
index 317b6b07a4..dae70b4c01 100644
--- a/bin/tests/shutdown_test.c
+++ b/bin/tests/shutdown_test.c
@@ -19,6 +19,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 #include <isc/assertions.h>
diff --git a/lib/dns/rootns.c b/lib/dns/rootns.c
index 5339da30a6..448a5258a5 100644
--- a/lib/dns/rootns.c
+++ b/lib/dns/rootns.c
@@ -18,6 +18,7 @@
 #include <config.h>
 
 #include <stddef.h>
+#include <string.h>
 
 #include <isc/assertions.h>
 #include <isc/error.h>