diff --git a/api/audio/audio_frame.cc b/api/audio/audio_frame.cc
index 6fb0ffaa0c..12ce426596 100644
--- a/api/audio/audio_frame.cc
+++ b/api/audio/audio_frame.cc
@@ -10,6 +10,8 @@
 
 #include "api/audio/audio_frame.h"
 
+#include <string.h>
+
 #include "rtc_base/checks.h"
 #include "rtc_base/timeutils.h"
 
diff --git a/audio/utility/audio_frame_operations.cc b/audio/utility/audio_frame_operations.cc
index a53629ae6f..ed7b7a8b8c 100644
--- a/audio/utility/audio_frame_operations.cc
+++ b/audio/utility/audio_frame_operations.cc
@@ -10,6 +10,7 @@
 
 #include "audio/utility/audio_frame_operations.h"
 
+#include <string.h>
 #include <algorithm>
 
 #include "rtc_base/checks.h"
diff --git a/common_audio/wav_header_unittest.cc b/common_audio/wav_header_unittest.cc
index c6f605f729..8b30530ad9 100644
--- a/common_audio/wav_header_unittest.cc
+++ b/common_audio/wav_header_unittest.cc
@@ -8,6 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include <string.h>
 #include <limits>
 
 #include "common_audio/wav_header.h"
diff --git a/modules/audio_processing/vad/standalone_vad.cc b/modules/audio_processing/vad/standalone_vad.cc
index f7ae449709..2640892cc2 100644
--- a/modules/audio_processing/vad/standalone_vad.cc
+++ b/modules/audio_processing/vad/standalone_vad.cc
@@ -10,6 +10,8 @@
 
 #include "modules/audio_processing/vad/standalone_vad.h"
 
+#include <string.h>
+
 #include "audio/utility/audio_frame_operations.h"
 #include "rtc_base/checks.h"
 #include "typedefs.h"  // NOLINT(build/include)
diff --git a/modules/audio_processing/vad/vad_audio_proc.cc b/modules/audio_processing/vad/vad_audio_proc.cc
index 98fcf1912d..6b559d182e 100644
--- a/modules/audio_processing/vad/vad_audio_proc.cc
+++ b/modules/audio_processing/vad/vad_audio_proc.cc
@@ -12,6 +12,7 @@
 
 #include <math.h>
 #include <stdio.h>
+#include <string.h>
 
 #include "common_audio/fft4g.h"
 #include "modules/audio_processing/vad/pitch_internal.h"