diff --git a/core/fxcodec/jbig2/JBig2_DocumentContext.h b/core/fxcodec/jbig2/JBig2_DocumentContext.h
index b2a44c5..3968a3e 100644
--- a/core/fxcodec/jbig2/JBig2_DocumentContext.h
+++ b/core/fxcodec/jbig2/JBig2_DocumentContext.h
@@ -7,6 +7,8 @@
 #ifndef CORE_FXCODEC_JBIG2_JBIG2_DOCUMENTCONTEXT_H_
 #define CORE_FXCODEC_JBIG2_JBIG2_DOCUMENTCONTEXT_H_
 
+#include <stdint.h>
+
 #include <list>
 #include <memory>
 #include <utility>
diff --git a/core/fxcrt/retain_ptr.h b/core/fxcrt/retain_ptr.h
index d87b76e..58b87f7 100644
--- a/core/fxcrt/retain_ptr.h
+++ b/core/fxcrt/retain_ptr.h
@@ -7,6 +7,7 @@
 
 #include <stdint.h>
 
+#include <cstddef>
 #include <functional>
 #include <memory>
 #include <type_traits>
diff --git a/core/fxcrt/span.h b/core/fxcrt/span.h
index 672e196..bb9b066 100644
--- a/core/fxcrt/span.h
+++ b/core/fxcrt/span.h
@@ -11,6 +11,7 @@
 #include <array>
 #include <iterator>
 #include <type_traits>
+#include <utility>
 
 #include "core/fxcrt/check.h"
 #include "core/fxcrt/compiler_specific.h"
diff --git a/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256.h b/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256.h
index 136cba9..6327227 100644
--- a/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256.h
+++ b/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256.h
@@ -7,6 +7,8 @@
 #ifndef FXBARCODE_COMMON_REEDSOLOMON_BC_REEDSOLOMONGF256_H_
 #define FXBARCODE_COMMON_REEDSOLOMON_BC_REEDSOLOMONGF256_H_
 
+#include <stdint.h>
+
 #include <array>
 #include <memory>
 #include <optional>
diff --git a/xfa/fgas/layout/cfgas_char.h b/xfa/fgas/layout/cfgas_char.h
index 314ac6c..693fe61 100644
--- a/xfa/fgas/layout/cfgas_char.h
+++ b/xfa/fgas/layout/cfgas_char.h
@@ -7,6 +7,7 @@
 #ifndef XFA_FGAS_LAYOUT_CFGAS_CHAR_H_
 #define XFA_FGAS_LAYOUT_CFGAS_CHAR_H_
 
+#include <stddef.h>
 #include <stdint.h>
 
 #include <vector>
diff --git a/xfa/fgas/layout/fgas_linebreak.cpp b/xfa/fgas/layout/fgas_linebreak.cpp
index a40c6fb..993d3e8 100644
--- a/xfa/fgas/layout/fgas_linebreak.cpp
+++ b/xfa/fgas/layout/fgas_linebreak.cpp
@@ -6,6 +6,8 @@
 
 #include "xfa/fgas/layout/fgas_linebreak.h"
 
+#include <stddef.h>
+
 #include <array>
 #include <iterator>