diff --git a/.travis.yml b/.travis.yml
index 3e39eef0..3242a3db 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -26,5 +26,4 @@ script:
 
 after_success:
   - go get github.com/mattn/goveralls
-  - $HOME/gopath/bin/goveralls -coverprofile=profile.cov -service=travis-ci
   - test "${TRAVIS_PULL_REQUEST}" = "false" && site/build-and-publish.sh
diff --git a/Makefile b/Makefile
index 79a465ef..6adf7dea 100644
--- a/Makefile
+++ b/Makefile
@@ -107,22 +107,7 @@ $(DOCKER_DISTRIB):
 	curl -o $(DOCKER_DISTRIB) $(DOCKER_DISTRIB_URL)
 
 tests:
-	echo "mode: count" > profile.cov
-	fail=0 ; \
-	for dir in $$(find . -type f -name '*_test.go' | xargs -n1 dirname | grep -v prog | sort -u); do \
-		go get -t -tags netgo $$dir ; \
-		output=$$(mktemp cover.XXXXXXXXXX) ; \
-		if ! go test -cpu 4 -tags netgo \
-			-covermode=count -coverprofile=$$output $$dir ; then \
-		fail=1 ; \
-        fi ; \
-	if [ -f $$output ]; then \
-		tail -n +2 <$$output >>profile.cov; \
-		rm $$output; \
-	fi \
-	done ; \
-	exit $$fail
-	go tool cover -html=profile.cov -o=coverage.html
+	@test/units.sh
 
 $(PUBLISH): publish_%:
 	$(SUDO) docker tag -f $(DOCKERHUB_USER)/$* $(DOCKERHUB_USER)/$*:$(WEAVE_VERSION)
@@ -133,6 +118,7 @@ publish: $(PUBLISH)
 
 clean:
 	-$(SUDO) docker rmi $(IMAGES)
+	go clean -r ./...
 	rm -f $(EXES) $(IMAGES_UPTODATE) $(WEAVE_EXPORT)
 	rm -f test/tls/*.pem
 
diff --git a/build/build.sh b/build/build.sh
index 7c6d13a4..25d3515b 100644
--- a/build/build.sh
+++ b/build/build.sh
@@ -6,7 +6,7 @@ export GOPATH
 
 WEAVE_SRC=$GOPATH/src/github.com/weaveworks/weave
 
-if [ $# -eq 0 ] ; then
+if [ $# -eq 0 -o "$1" = "tests" ] ; then
     # No arguments.  Expect that the weave repo will be bind-mounted
     # into $GOPATH
     if ! [ -e $WEAVE_SRC ] ; then
@@ -35,7 +35,12 @@ EOF
     echo "weave:x:$uid:$gid::$WEAVE_SRC:/bin/sh" >>/etc/passwd
     echo "weave:*:::::::" >>/etc/shadow
     echo "weave	ALL=(ALL)	NOPASSWD: ALL" >>/etc/sudoers
-    su weave -c "PATH=$PATH make -C $WEAVE_SRC build"
+
+    if [ "$1" = "tests" ] ; then
+        su weave -c "PATH=$PATH make -C $WEAVE_SRC tests"
+    else
+        su weave -c "PATH=$PATH make -C $WEAVE_SRC build"
+    fi
 else
     # There are arguments to pass to git-clone
     mkdir -p ${WEAVE_SRC%/*}
diff --git a/circle.yml b/circle.yml
index 5ac5cc3d..0d1298f8 100644
--- a/circle.yml
+++ b/circle.yml
@@ -35,6 +35,8 @@ dependencies:
 
 test:
   override:
+    - test "$CIRCLE_NODE_INDEX" != "0" || (docker run -v /var/run/docker.sock:/run/docker.sock -v /home/ubuntu:/home/go -e "COVERDIR=test/coverage" weaveworks/weave-build tests):
+        parallel: true
     - docker run -v /var/run/docker.sock:/run/docker.sock -v /home/ubuntu:/home/go -e COVERAGE=true weaveworks/weave-build:
         parallel: true
     - cd $SRCDIR/test; ./gce.sh setup:
@@ -52,5 +54,6 @@ teardown:
   pre:
     - test "$CIRCLE_NODE_INDEX" != "0" || (cd $SRCDIR/test; ./gen_coverage_reports.sh):
         parallel: true
+    - test "$CIRCLE_NODE_INDEX" != "0" || (go get github.com/mattn/goveralls && goveralls -repotoken $COVERALLS_REPO_TOKEN -coverprofile=$SRCDIR/test/profile.cov -service=circleci || true)
     - test "$CIRCLE_NODE_INDEX" != "0" || (cd $SRCDIR/test; cp coverage.* $CIRCLE_ARTIFACTS):
         parallel: true
diff --git a/test/units.sh b/test/units.sh
new file mode 100755
index 00000000..2a383c7a
--- /dev/null
+++ b/test/units.sh
@@ -0,0 +1,28 @@
+#!/bin/bash
+
+go get github.com/weaveworks/weave/testing/cover
+
+if [ -n "$COVERDIR" ] ; then
+	coverdir="$COVERDIR"
+else
+	coverdir=$(mktemp -d coverage.XXXXXXXXXX)
+fi
+
+mkdir -p $coverdir
+fail=0
+
+for dir in $(find . -type f -name '*_test.go' | xargs -n1 dirname | grep -v prog | sort -u); do
+	go get -t -tags netgo $dir
+	output=$(mktemp $coverdir/unit.XXXXXXXXXX)
+	if ! go test -cpu 4 -tags netgo -covermode=count -coverprofile=$output $dir ; then
+		fail=1
+	fi
+done
+
+if [ -z "$COVERDIR" ] ; then
+	cover $coverdir/* >profile.cov
+	rm -rf $coverdir
+	go tool cover -html=profile.cov -o=coverage.html
+fi
+
+exit $fail