diff --git a/testsuite/testutils.c b/testsuite/testutils.c
index 6fd5f1afafd6ac6f01d7b4a770f64c246bc11502..ee0cd5e33db4f56daef049130127b2f8414cfd8b 100644
--- a/testsuite/testutils.c
+++ b/testsuite/testutils.c
@@ -4,6 +4,7 @@
 
 #include <ctype.h>
 #include <stdlib.h>
+#include <string.h>
 
 int
 decode_hex(uint8_t *dst, const char *hex)
diff --git a/twofish.c b/twofish.c
index 41a2eaa724effab1fd9041c1f4e6a85c55fce7e7..100a39c7d8c428227b6b9efe5d74362b0ce40558 100644
--- a/twofish.c
+++ b/twofish.c
@@ -36,6 +36,7 @@
 #include "macros.h"
 
 #include <assert.h>
+#include <string.h>
 
 /* Bitwise rotations on 32-bit words.  These are defined as macros that
  * evaluate their argument twice, so do not apply to any expressions with