--- a/js/src/builtin/Intl.cpp
+++ b/js/src/builtin/Intl.cpp
@@ -72,16 +72,43 @@ using icu::NumberingSystem;
  * against ICU. However, we still want to compile this code in order to prevent
  * bit rot. The following stub implementations for ICU functions make this
  * possible. The functions using them should never be called, so they assert
  * and return error codes. Signatures adapted from ICU header files locid.h,
  * numsys.h, ucal.h, ucol.h, udat.h, udatpg.h, uenum.h, unum.h; see the ICU
  * directory for license.
  */
 
+typedef bool UBool;
+typedef char16_t UChar;
+typedef double UDate;
+
+enum UErrorCode {
+    U_ZERO_ERROR,
+    U_BUFFER_OVERFLOW_ERROR,
+};
+
+static inline UBool
+U_FAILURE(UErrorCode code)
+{
+    MOZ_CRASH("U_FAILURE: Intl API disabled");
+}
+
+inline const UChar*
+Char16ToUChar(const char16_t* chars)
+{
+    MOZ_CRASH("Char16ToUChar: Intl API disabled");
+}
+
+inline UChar*
+Char16ToUChar(char16_t* chars)
+{
+    MOZ_CRASH("Char16ToUChar: Intl API disabled");
+}
+
 static int32_t
 u_strlen(const UChar* s)
 {
     MOZ_CRASH("u_strlen: Intl API disabled");
 }
 
 struct UEnumeration;
 

--- a/js/src/builtin/Intl.h
+++ b/js/src/builtin/Intl.h
@@ -3,17 +3,19 @@
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef builtin_Intl_h
 #define builtin_Intl_h
 
 #include "NamespaceImports.h"
+#if ENABLE_INTL_API
 #include "unicode/utypes.h"
+#endif
 
 /*
  * The Intl module specified by standard ECMA-402,
  * ECMAScript Internationalization API Specification.
  */
 
 namespace js {
 
@@ -174,26 +176,28 @@ intl_patternForSkeleton(JSContext* cx, u
  *
  * Spec: ECMAScript Internationalization API Specification, 12.3.2.
  *
  * Usage: formatted = intl_FormatDateTime(dateTimeFormat, x)
  */
 extern MOZ_MUST_USE bool
 intl_FormatDateTime(JSContext* cx, unsigned argc, Value* vp);
 
+#if ENABLE_INTL_API
 /**
  * Cast char16_t* strings to UChar* strings used by ICU.
  */
 inline const UChar*
 Char16ToUChar(const char16_t* chars)
 {
   return reinterpret_cast<const UChar*>(chars);
 }
 
 inline UChar*
 Char16ToUChar(char16_t* chars)
 {
   return reinterpret_cast<UChar*>(chars);
 }
+#endif // ENABLE_INTL_API
 
 } // namespace js
 
 #endif /* builtin_Intl_h */