deleted file mode 100644
--- a/uriloader/exthandler/tests/Makefile.in
+++ /dev/null
@@ -1,11 +0,0 @@
-# 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/.
-
-include $(topsrcdir)/config/rules.mk
-
-# need the executable for running the xpcshell unit tests
-ifneq (,$(SIMPLE_PROGRAMS))
-libs::
-	$(INSTALL) $(SIMPLE_PROGRAMS) $(DEPTH)/_tests/xpcshell/$(relativesrcdir)/unit
-endif

--- a/uriloader/exthandler/tests/moz.build
+++ b/uriloader/exthandler/tests/moz.build
@@ -14,11 +14,16 @@ BROWSER_CHROME_MANIFESTS += ['mochitest/
 # test cases with the string "content_encoding" in their names.
 if not CONFIG['MOZ_JSDOWNLOADS']:
     XPCSHELL_TESTS_MANIFESTS += ['unit_ipc/xpcshell.ini']
 
 GeckoSimplePrograms([
     'WriteArgument',
 ], linkage=None)
 
+if CONFIG['COMPILE_ENVIRONMENT']:
+    TEST_HARNESS_FILES.xpcshell.uriloader.exthandler.tests.unit += [
+        '!WriteArgument%s' % CONFIG['BIN_SUFFIX']
+    ]
+
 USE_LIBS += [
     'nspr',
 ]