diff --git a/src/io-util.hh b/src/io-util.hh
index 40f9f84ae..a3fce53d7 100644
--- a/src/io-util.hh
+++ b/src/io-util.hh
@@ -6,6 +6,7 @@
 #include <vector>
 #include <algorithm>
 #include <map>
+#include <cstdint>
 
 #ifdef TINYUSDZ_ANDROID_LOAD_FROM_ASSETS
 #include <android/asset_manager.h>
diff --git a/src/str-util.hh b/src/str-util.hh
index 324ea4e3b..be90d9882 100644
--- a/src/str-util.hh
+++ b/src/str-util.hh
@@ -8,6 +8,7 @@
 #include <string>
 #include <vector>
 #include <set>
+#include <cstdint>
 
 namespace tinyusdz {
 
diff --git a/src/tydra/facial.cc b/src/tydra/facial.cc
index 95b0cc4b7..6f6a3d2d3 100644
--- a/src/tydra/facial.cc
+++ b/src/tydra/facial.cc
@@ -3,6 +3,7 @@
 
 #include <array>
 #include <string>
+#include <cstdint>
 
 //
 #include "facial.hh"