diff --git a/libavutil/hash.c b/libavutil/hash.c
index 75edb6db78..d626c31181 100644
--- a/libavutil/hash.c
+++ b/libavutil/hash.c
@@ -17,6 +17,8 @@
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
+
+#include <stddef.h>
 #include <stdint.h>
 #include "hash.h"
 
diff --git a/libavutil/hash.h b/libavutil/hash.h
index 7693e6bf0d..af4719e423 100644
--- a/libavutil/hash.h
+++ b/libavutil/hash.h
@@ -27,6 +27,7 @@
 #ifndef AVUTIL_HASH_H
 #define AVUTIL_HASH_H
 
+#include <stddef.h>
 #include <stdint.h>
 
 #include "version.h"
diff --git a/libavutil/murmur3.c b/libavutil/murmur3.c
index 7961752515..3e85c3c94f 100644
--- a/libavutil/murmur3.c
+++ b/libavutil/murmur3.c
@@ -17,6 +17,8 @@
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
+
+#include <stddef.h>
 #include <stdint.h>
 #include "mem.h"
 #include "intreadwrite.h"
diff --git a/libavutil/murmur3.h b/libavutil/murmur3.h
index 1b09175c1e..b3b3a07de2 100644
--- a/libavutil/murmur3.h
+++ b/libavutil/murmur3.h
@@ -27,6 +27,7 @@
 #ifndef AVUTIL_MURMUR3_H
 #define AVUTIL_MURMUR3_H
 
+#include <stddef.h>
 #include <stdint.h>
 
 #include "version.h"
diff --git a/libavutil/ripemd.c b/libavutil/ripemd.c
index 4f1c4ea899..89d69cc23d 100644
--- a/libavutil/ripemd.c
+++ b/libavutil/ripemd.c
@@ -19,6 +19,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <stddef.h>
 #include <string.h>
 
 #include "attributes.h"
diff --git a/libavutil/ripemd.h b/libavutil/ripemd.h
index 0db6858ff3..921aa66684 100644
--- a/libavutil/ripemd.h
+++ b/libavutil/ripemd.h
@@ -28,6 +28,7 @@
 #ifndef AVUTIL_RIPEMD_H
 #define AVUTIL_RIPEMD_H
 
+#include <stddef.h>
 #include <stdint.h>
 
 #include "attributes.h"