diff --git a/build/virtualenv/Makefile.in b/build/virtualenv/Makefile.in
index d050eaf7e97..74220c727e8 100644
--- a/build/virtualenv/Makefile.in
+++ b/build/virtualenv/Makefile.in
@@ -9,7 +9,26 @@ VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
+# Paths here are topsrcdir-relative, and
+# must be in dependency-order.
+setuptools_packages := \
+  other-licenses/simplejson-2.1.1 \
+  testing/mozbase/manifestdestiny \
+  testing/mozbase/mozinfo \
+  testing/mozbase/mozinstall \
+  testing/mozbase/mozlog \
+  testing/mozbase/mozprocess \
+  testing/mozbase/mozprofile \
+  testing/mozbase/mozrunner \
+  $(NULL)
+
+
+define install_setuptools_package
+cd $(topsrcdir)/$(1)/; $(PYTHON) setup.py develop
+
+endef
+
 default::
-# install some packages
+	$(foreach package,$(setuptools_packages),$(call install_setuptools_package,$(package)))
 
 include $(topsrcdir)/config/rules.mk