diff --git a/modules/audio_coding/acm2/acm_receive_test.h b/modules/audio_coding/acm2/acm_receive_test.h
index 657a12467a..c7e7da6e36 100644
--- a/modules/audio_coding/acm2/acm_receive_test.h
+++ b/modules/audio_coding/acm2/acm_receive_test.h
@@ -11,6 +11,7 @@
 #ifndef MODULES_AUDIO_CODING_ACM2_ACM_RECEIVE_TEST_H_
 #define MODULES_AUDIO_CODING_ACM2_ACM_RECEIVE_TEST_H_
 
+#include <stddef.h> // for size_t
 #include <memory>
 #include <string>
 
@@ -30,7 +31,7 @@ class PacketSource;
 
 class AcmReceiveTestOldApi {
  public:
-  enum NumOutputChannels {
+  enum NumOutputChannels : size_t {
     kArbitraryChannels = 0,
     kMonoOutput = 1,
     kStereoOutput = 2
diff --git a/p2p/base/portallocator.h b/p2p/base/portallocator.h
index 25a6d48fa5..f8e813f502 100644
--- a/p2p/base/portallocator.h
+++ b/p2p/base/portallocator.h
@@ -111,7 +111,7 @@ const uint32_t kMinimumStepDelay = 50;
 constexpr int kDefaultMaxIPv6Networks = 5;
 
 // CF = CANDIDATE FILTER
-enum {
+enum : uint32_t {
   CF_NONE = 0x0,
   CF_HOST = 0x1,
   CF_REFLEXIVE = 0x2,