diff --git a/js/src/Makefile.in b/js/src/Makefile.in
index 4944d31..4176e14 100644
--- a/js/src/Makefile.in
+++ b/js/src/Makefile.in
@@ -237,12 +237,17 @@ endif
 # ICU headers need to be available whether we build with the complete
 # Internationalization API or not - ICU stubs rely on them.
 
+ifdef MOZ_NATIVE_ICU
+LOCAL_INCLUDES += $(MOZ_ICU_CFLAGS)
+else
 LOCAL_INCLUDES += \
   -I$(topsrcdir)/../../intl/icu/source/common \
   -I$(topsrcdir)/../../intl/icu/source/i18n \
   $(NULL)
+endif
 
 ifdef ENABLE_INTL_API
+ifndef MOZ_NATIVE_ICU
 
 ifeq ($(OS_ARCH),WINNT)
   # Parallel gmake is buggy on Windows
@@ -271,6 +276,7 @@ distclean clean::
 	$(call SUBMAKE,$@,intl/icu)
 
 endif
+endif
 
 #
 # END ECMAScript Internationalization API
@@ -403,7 +409,11 @@ ifneq (,$(MOZ_ZLIB_LIBS)$(MOZ_GLUE_LDFLAGS))
 DEFINES += -DUSE_ZLIB
 endif
 
-SHARED_LIBRARY_LIBS += $(ICU_LIBS)
+ifdef MOZ_NATIVE_ICU
+EXTRA_DSO_LDOPTS += $(MOZ_ICU_LIBS)
+else
+SHARED_LIBRARY_LIBS += $(MOZ_ICU_LIBS)
+endif
 
 # Prevent floating point errors caused by VC++ optimizations
 ifdef _MSC_VER
diff --git a/js/src/config/Makefile.in b/js/src/config/Makefile.in
index 5f60d15..e1fe1f8 100644
--- a/js/src/config/Makefile.in
+++ b/js/src/config/Makefile.in
@@ -59,6 +59,7 @@ export:: \
   $(call mkdir_deps,system_wrappers_js) \
   $(NULL)
 	$(PYTHON) $(srcdir)/Preprocessor.py $(DEFINES) $(ACDEFINES) \
+		-DMOZ_NATIVE_ICU=$(MOZ_NATIVE_ICU) \
 		$(srcdir)/system-headers | $(PERL) $(srcdir)/make-system-wrappers.pl system_wrappers_js
 	$(INSTALL) system_wrappers_js $(DIST)
 
diff --git a/js/src/config/system-headers b/js/src/config/system-headers
index b52aed6..1ca7420 100644
--- a/js/src/config/system-headers
+++ b/js/src/config/system-headers
@@ -1132,3 +1132,14 @@ kvm.h
 spawn.h
 err.h
 xlocale.h
+#if MOZ_NATIVE_ICU==1
+unicode/locid.h
+unicode/numsys.h
+unicode/ucal.h
+unicode/ucol.h
+unicode/udat.h
+unicode/udatpg.h
+unicode/uenum.h
+unicode/unum.h
+unicode/ustring.h
+#endif
diff --git a/js/src/configure.in b/js/src/configure.in
index 4bccbe3..d535491 100644
--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -4409,6 +4409,16 @@ fi
 dnl ========================================================
 dnl ECMAScript Internationalization API Support (uses ICU)
 dnl ========================================================
+ICU_LIB_NAMES=
+MOZ_NATIVE_ICU=
+MOZ_ARG_WITH_BOOL(system-icu,
+[  --with-system-icu
+                          Use system icu (located with pkgconfig)],
+    MOZ_NATIVE_ICU=1)
+
+if test -n "$MOZ_NATIVE_ICU"; then
+    PKG_CHECK_MODULES(MOZ_ICU, icu-i18n >= 50.1)
+fi
 
 if test -n "$JS_STANDALONE"; then
     ENABLE_INTL_API=1
@@ -4421,37 +4431,34 @@ MOZ_ARG_ENABLE_BOOL(intl-api,
 dnl Settings for the implementation of the ECMAScript Internationalization API
 if test -n "$ENABLE_INTL_API"; then
     AC_DEFINE(ENABLE_INTL_API)
-    # We build ICU as a static library.
-    AC_DEFINE(U_STATIC_IMPLEMENTATION)
-
-    case "$OS_TARGET" in
-        WINNT)
-            ICU_LIB_NAMES="icuin icuuc icudt"
-            ;;
-        Darwin|Linux)
-            ICU_LIB_NAMES="icui18n icuuc icudata"
-            ;;
-        *)
-            AC_MSG_ERROR([ECMAScript Internationalization API is not yet supported on this platform])
-    esac
-
-    ICU_LIBS='$(call EXPAND_LIBNAME_PATH,$(ICU_LIB_NAMES),$(DEPTH)/intl/icu/lib)'
-else
-    ICU_LIB_NAMES=
-    ICU_LIBS=
+    if test -z "$MOZ_NATIVE_ICU"; then
+        case "$OS_TARGET" in
+            WINNT)
+                ICU_LIB_NAMES="icuin icuuc icudt"
+                ;;
+            Darwin|Linux|DragonFly|FreeBSD|NetBSD|OpenBSD)
+                ICU_LIB_NAMES="icui18n icuuc icudata"
+                ;;
+            *)
+                AC_MSG_ERROR([ECMAScript Internationalization API is not yet supported on this platform])
+        esac
+        MOZ_ICU_LIBS='$(call EXPAND_LIBNAME_PATH,$(ICU_LIB_NAMES),$(DEPTH)/intl/icu/lib)'
+    fi
 fi
 
 AC_SUBST(ENABLE_INTL_API)
 AC_SUBST(ICU_LIB_NAMES)
-AC_SUBST(ICU_LIBS)
-
-dnl Source files that use ICU should have control over which parts of the ICU
-dnl namespace they want to use.
-AC_DEFINE(U_USING_ICU_NAMESPACE,0)
-
+AC_SUBST(MOZ_ICU_LIBS)
+AC_SUBST(MOZ_NATIVE_ICU)
 
 dnl Settings for ICU
-if test -n "$ENABLE_INTL_API" ; then
+if test -n "$ENABLE_INTL_API" -a -z "$MOZ_NATIVE_ICU"; then
+    dnl We build ICU as a static library.
+    AC_DEFINE(U_STATIC_IMPLEMENTATION)
+ 
+    dnl Source files that use ICU should have control over which parts of the ICU
+    dnl namespace they want to use.
+    AC_DEFINE(U_USING_ICU_NAMESPACE,0)
     # Set ICU compile options
     ICU_CPPFLAGS=""
     # don't use icu namespace automatically in client code
diff --git a/js/src/gdb/Makefile.in b/js/src/gdb/Makefile.in
index 288934a..a582dfe 100644
--- a/js/src/gdb/Makefile.in
+++ b/js/src/gdb/Makefile.in
@@ -19,6 +19,10 @@ LIBS = $(DEPTH)/$(LIB_PREFIX)js_static.$(LIB_SUFFIX) $(NSPR_LIBS) $(MOZ_ZLIB_LIB
 
 LOCAL_INCLUDES += -I$(topsrcdir) -I..
 
+ifdef MOZ_NATIVE_ICU
+EXTRA_LIBS += $(MOZ_ICU_LIBS)
+endif
+
 EXTRA_LIBS += $(MOZ_FFI_LIBS)
 
 # Place a GDB Python auto-load file next to the gdb-tests executable, both
diff --git a/js/src/jsapi-tests/Makefile.in b/js/src/jsapi-tests/Makefile.in
index 5f7d594..10d7054 100644
--- a/js/src/jsapi-tests/Makefile.in
+++ b/js/src/jsapi-tests/Makefile.in
@@ -20,6 +20,10 @@ LIBS      = $(DEPTH)/$(LIB_PREFIX)js_static.$(LIB_SUFFIX) $(NSPR_LIBS) $(MOZ_ZLI
 
 LOCAL_INCLUDES += -I$(topsrcdir) -I..
 
+ifdef MOZ_NATIVE_ICU
+EXTRA_LIBS += $(MOZ_ICU_LIBS)
+endif
+
 EXTRA_LIBS += $(MOZ_FFI_LIBS)
 
 ifdef QEMU_EXE
diff --git a/js/src/shell/Makefile.in b/js/src/shell/Makefile.in
index 2e1df09..db66c69 100644
--- a/js/src/shell/Makefile.in
+++ b/js/src/shell/Makefile.in
@@ -27,6 +27,9 @@ LIBS      = $(NSPR_LIBS) $(EDITLINE_LIBS) $(DEPTH)/$(LIB_PREFIX)js_static.$(LIB_
 ifdef MOZ_NATIVE_FFI
 EXTRA_LIBS += $(MOZ_FFI_LIBS)
 endif
+ifdef MOZ_NATIVE_ICU
+EXTRA_LIBS += $(MOZ_ICU_LIBS)
+endif
 
 LOCAL_INCLUDES += -I$(topsrcdir) -I..