diff --git a/b2g/app/Makefile.in b/b2g/app/Makefile.in
index bf5568895bd..89045dd46bd 100644
--- a/b2g/app/Makefile.in
+++ b/b2g/app/Makefile.in
@@ -124,14 +124,9 @@ else # MOZ_WIDGET_TOOLKIT != cocoa
 libs::
 ifdef LIBXUL_SDK
 	cp $(LIBXUL_DIST)/bin/xulrunner-stub$(BIN_SUFFIX) $(DIST)/bin/$(APP_BINARY)
-endif
-ifndef SKIP_COPY_XULRUNNER
-ifdef LIBXUL_SDK
 	$(NSINSTALL) -D $(DIST)/bin/xulrunner
 	(cd $(LIBXUL_SDK)/bin && tar $(TAR_CREATE_FLAGS) - .) | (cd $(DIST)/bin/xulrunner && tar -xf -)
 endif
-endif # SKIP_COPY_XULRUNNER
-
 	$(NSINSTALL) -D $(DIST)/bin/chrome/icons/default
 
 # Copy the app icon for b2g-desktop
diff --git a/browser/app/Makefile.in b/browser/app/Makefile.in
index 2ab4158433e..4fb9b57d69e 100644
--- a/browser/app/Makefile.in
+++ b/browser/app/Makefile.in
@@ -135,7 +135,6 @@ tools repackage:: $(PROGRAM)
 endif
 
 ifdef LIBXUL_SDK #{
-ifndef SKIP_COPY_XULRUNNER #{
 libs::
 ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT)) #{
 	rsync -a --copy-unsafe-links $(LIBXUL_DIST)/XUL.framework $(dist_dest)/Contents/Frameworks
@@ -143,5 +142,4 @@ else
 	$(NSINSTALL) -D $(DIST)/bin/xulrunner
 	(cd $(LIBXUL_SDK)/bin && tar $(TAR_CREATE_FLAGS) - .) | (cd $(DIST)/bin/xulrunner && tar -xf -)
 endif #} cocoa
-endif #} SKIP_COPY_XULRUNNER
 endif #} LIBXUL_SDK
diff --git a/browser/installer/Makefile.in b/browser/installer/Makefile.in
index 1883ad7d919..082a97b9f3a 100644
--- a/browser/installer/Makefile.in
+++ b/browser/installer/Makefile.in
@@ -16,11 +16,9 @@ MOZ_PKG_MANIFEST_P += $(topsrcdir)/b2g/installer/package-manifest.in
 endif
 
 # Some files have been already bundled with xulrunner
-ifndef SYSTEM_LIBXUL
 ifndef MOZ_MULET
 MOZ_PKG_FATAL_WARNINGS = 1
 endif
-endif
 
 DEFINES += -DAB_CD=$(AB_CD) -DMOZ_APP_NAME=$(MOZ_APP_NAME) -DPREF_DIR=$(PREF_DIR)
 
diff --git a/config/rules.mk b/config/rules.mk
index 3a6a48d52ad..3d25ab0955e 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -43,11 +43,6 @@ endif
 
 EXEC			= exec
 
-# Don't copy xulrunner files at install time, when using system xulrunner
-ifdef SYSTEM_LIBXUL
-  SKIP_COPY_XULRUNNER=1
-endif
-
 # ELOG prints out failed command when building silently (gmake -s). Pymake
 # prints out failed commands anyway, so ELOG just makes things worse by
 # forcing shell invocations.
diff --git a/configure.in b/configure.in
index b079b4b3dc9..a365dbef8eb 100644
--- a/configure.in
+++ b/configure.in
@@ -3422,33 +3422,11 @@ MOZ_ARG_HEADER(External Packages)
 
 MOZ_ARG_WITH_STRING(libxul-sdk,
 [  --with-libxul-sdk=PFX   Use the libXUL SDK at <PFX>],
-  LIBXUL_SDK_DIR=$withval)
+  AC_MSG_ERROR([--with-libxul-sdk is not supported anymore.]))
 
-if test "$LIBXUL_SDK_DIR" = "yes"; then
-    AC_MSG_ERROR([--with-libxul-sdk must specify a path])
-elif test -n "$LIBXUL_SDK_DIR" -a "$LIBXUL_SDK_DIR" != "no"; then
-    LIBXUL_SDK=`cd "$LIBXUL_SDK_DIR" && pwd`
-
-    if test ! -f "$LIBXUL_SDK/include/xpcom-config.h"; then
-        AC_MSG_ERROR([$LIBXUL_SDK/include/xpcom-config.h doesn't exist])
-    fi
-
-fi
-AC_SUBST(LIBXUL_SDK)
-
-if test -n "$LIBXUL_SDK"; then
-    LIBXUL_DIST="$LIBXUL_SDK"
-else
-    LIBXUL_DIST="$MOZ_BUILD_ROOT/dist"
-fi
+LIBXUL_DIST="$MOZ_BUILD_ROOT/dist"
 AC_SUBST(LIBXUL_DIST)
 
-SYSTEM_LIBXUL=
-
-MOZ_ARG_WITH_BOOL(system-libxul,
-[  --with-system-libxul    Use system installed libxul SDK],
-    SYSTEM_LIBXUL=1)
-
 dnl ========================================================
 dnl = If NSPR was not detected in the system,
 dnl = use the one in the source tree (mozilla/nsprpub)
@@ -8730,7 +8708,6 @@ HOST_CXXFLAGS=`echo \
     $HOST_CXXFLAGS \
     $_DEPEND_CFLAGS`
 
-AC_SUBST(SYSTEM_LIBXUL)
 AC_SUBST(MOZ_NATIVE_JPEG)
 AC_SUBST(MOZ_NATIVE_PNG)
 AC_SUBST(MOZ_NATIVE_BZ2)
diff --git a/mobile/android/app/Makefile.in b/mobile/android/app/Makefile.in
index 8aaa75ad435..30ec92c9dd4 100644
--- a/mobile/android/app/Makefile.in
+++ b/mobile/android/app/Makefile.in
@@ -26,11 +26,8 @@ libs::
 ifdef LIBXUL_SDK
 	cp $(LIBXUL_DIST)/bin/xulrunner-stub$(BIN_SUFFIX) $(DIST)/bin/$(APP_BINARY)
 endif
-ifndef SKIP_COPY_XULRUNNER #{
 ifdef LIBXUL_SDK
 	$(NSINSTALL) -D $(DIST)/bin/xulrunner
 	(cd $(LIBXUL_SDK)/bin && tar $(TAR_CREATE_FLAGS) - .) | (cd $(DIST)/bin/xulrunner && tar -xf -)
 endif
-endif #} SKIP_COPY_XULRUNNER
-
 	$(NSINSTALL) -D $(DIST)/bin/chrome/icons/default