diff --git a/icu4c/source/common/unicode/char16ptr.h b/icu4c/source/common/unicode/char16ptr.h
index 4035ce9bbbc..27efa5da2d0 100644
--- a/icu4c/source/common/unicode/char16ptr.h
+++ b/icu4c/source/common/unicode/char16ptr.h
@@ -26,7 +26,7 @@ U_NAMESPACE_BEGIN
  */
 #ifdef U_ALIASING_BARRIER
     // Use the predefined value.
-#elif defined(__clang__) || defined(__GNUC__)
+#elif (defined(__clang__) || defined(__GNUC__)) && U_PLATFORM != U_PF_BROWSER_NATIVE_CLIENT
 #   define U_ALIASING_BARRIER(ptr) asm volatile("" : : "rm"(ptr) : "memory")
 #endif
 
diff --git a/icu4c/source/common/unicode/platform.h b/icu4c/source/common/unicode/platform.h
index b553b6878da..e6d449b57ab 100644
--- a/icu4c/source/common/unicode/platform.h
+++ b/icu4c/source/common/unicode/platform.h
@@ -150,7 +150,7 @@
 #   define U_PLATFORM U_PF_ANDROID
     /* Android wchar_t support depends on the API level. */
 #   include <android/api-level.h>
-#elif defined(__native_client__)
+#elif defined(__pnacl__) || defined(__native_client__)
 #   define U_PLATFORM U_PF_BROWSER_NATIVE_CLIENT
 #elif defined(linux) || defined(__linux__) || defined(__linux)
 #   define U_PLATFORM U_PF_LINUX