diff --git a/include/base/cef_basictypes.h b/include/base/cef_basictypes.h
index 80a684d8d..a53c295ea 100644
--- a/include/base/cef_basictypes.h
+++ b/include/base/cef_basictypes.h
@@ -72,15 +72,16 @@ typedef int                 int32;
 typedef unsigned int       uint32;
 #endif
 
-// UTF-16 character type
+#endif  // !BUILDING_CEF_SHARED
+
+// UTF-16 character type.
+// This should be kept synchronized with base/strings/string16.h
 #ifndef char16
-#if defined(WIN32)
+#if defined(WCHAR_T_IS_UTF16)
 typedef wchar_t             char16;
-#else
+#elif defined(WCHAR_T_IS_UTF32)
 typedef unsigned short      char16;
 #endif
 #endif
 
-#endif  // !BUILDING_CEF_SHARED
-
 #endif  // CEF_INCLUDE_BASE_CEF_BASICTYPES_H_
diff --git a/include/internal/cef_string_types.h b/include/internal/cef_string_types.h
index 493dc7e65..ab21fe84c 100644
--- a/include/internal/cef_string_types.h
+++ b/include/internal/cef_string_types.h
@@ -38,26 +38,13 @@
 
 #include <stddef.h>
 
-#include "include/base/cef_build.h"
+#include "include/base/cef_basictypes.h"
 #include "include/internal/cef_export.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-// CEF character type definitions. wchar_t is 2 bytes on Windows and 4 bytes on
-// most other platforms.
-
-#if defined(OS_WIN)
-typedef wchar_t char16;
-#else  // !OS_WIN
-typedef unsigned short char16;  // NOLINT (runtime/int)
-#ifndef WCHAR_T_IS_UTF32
-#define WCHAR_T_IS_UTF32
-#endif  // WCHAR_T_IS_UTF32
-#endif  // !OS_WIN
-
-
 // CEF string type definitions. Whomever allocates |str| is responsible for
 // providing an appropriate |dtor| implementation that will free the string in
 // the same memory space. When reusing an existing string structure make sure
diff --git a/include/internal/cef_types.h b/include/internal/cef_types.h
index b378596fd..2790f2c4e 100644
--- a/include/internal/cef_types.h
+++ b/include/internal/cef_types.h
@@ -32,7 +32,7 @@
 #define CEF_INCLUDE_INTERNAL_CEF_TYPES_H_
 #pragma once
 
-#include "include/base/cef_build.h"
+#include "include/base/cef_basictypes.h"
 #include "include/internal/cef_string.h"
 #include "include/internal/cef_string_list.h"
 #include "include/internal/cef_time.h"
@@ -46,45 +46,6 @@
 #include "include/internal/cef_types_linux.h"
 #endif
 
-#include <limits.h>         // For UINT_MAX
-#include <stddef.h>         // For size_t
-
-// The NSPR system headers define 64-bit as |long| when possible, except on
-// Mac OS X.  In order to not have typedef mismatches, we do the same on LP64.
-//
-// On Mac OS X, |long long| is used for 64-bit types for compatibility with
-// <inttypes.h> format macros even in the LP64 model.
-#if defined(__LP64__) && !defined(OS_MACOSX) && !defined(OS_OPENBSD)
-typedef long                int64;  // NOLINT(runtime/int)
-typedef unsigned long       uint64;  // NOLINT(runtime/int)
-#else
-typedef long long           int64;  // NOLINT(runtime/int)
-typedef unsigned long long  uint64;  // NOLINT(runtime/int)
-#endif
-
-// TODO: Remove these type guards.  These are to avoid conflicts with
-// obsolete/protypes.h in the Gecko SDK.
-#ifndef _INT32
-#define _INT32
-typedef int                 int32;
-#endif
-
-// TODO: Remove these type guards.  These are to avoid conflicts with
-// obsolete/protypes.h in the Gecko SDK.
-#ifndef _UINT32
-#define _UINT32
-typedef unsigned int       uint32;
-#endif
-
-// UTF-16 character type
-#ifndef char16
-#if defined(WIN32)
-typedef wchar_t             char16;
-#else
-typedef unsigned short      char16;
-#endif
-#endif
-
 // 32-bit ARGB color value, not premultiplied. The color components are always
 // in a known order. Equivalent to the SkColor type.
 typedef uint32              cef_color_t;