diff --git a/.travis.yml b/.travis.yml
index f5a58c6091114117aec994fc9a21ab3f3a6d6744..60d8db7471b2b86f5d83076967ac4048478d22a3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,8 +30,10 @@ before_install:
         docker push $DOCKER_IMG;
       fi
     fi
-  # Build Cooja
-  - ant -q -f $CNG_HOST_PATH/tools/cooja/build.xml jar
+  # Build Cooja conditionally
+  - if [ ${BUILD_COOJA:-false} = true ] ; then
+      ant -q -f $CNG_HOST_PATH/tools/cooja/build.xml jar ;
+    fi
   # Set permissions for Docker mount
   - sudo chgrp -hR 1000 $CNG_HOST_PATH
 
@@ -55,14 +57,14 @@ env:
     - TEST_NAME='compile-base'
     - TEST_NAME='compile-arm-ports-01'
     - TEST_NAME='compile-arm-ports-02'
-    - TEST_NAME='rpl-lite'
-    - TEST_NAME='rpl-classic'
-    - TEST_NAME='tun-rpl-br'
+    - TEST_NAME='rpl-lite' BUILD_COOJA=true
+    - TEST_NAME='rpl-classic' BUILD_COOJA=true
+    - TEST_NAME='tun-rpl-br' BUILD_COOJA=true
     - TEST_NAME='coap-lwm2m'
-    - TEST_NAME='simulation-base'
-    - TEST_NAME='ieee802154'
+    - TEST_NAME='simulation-base' BUILD_COOJA=true
+    - TEST_NAME='ieee802154' BUILD_COOJA=true
     - TEST_NAME='compile-nxp-ports'
     - TEST_NAME='documentation'
     - TEST_NAME='compile-tools'
     - TEST_NAME='native-runs'
-    - TEST_NAME='ipv6'
+    - TEST_NAME='ipv6' BUILD_COOJA=true
diff --git a/tests/Makefile.script-test b/tests/Makefile.script-test
index e4dd0da6a6132d14b5481e38619b22e5f83bed87..e58acec80fc3ae7681282090afc80b7cb21b8f66 100644
--- a/tests/Makefile.script-test
+++ b/tests/Makefile.script-test
@@ -5,18 +5,14 @@ CONTIKI=../..
 
 all: clean summary
 
-summary: cooja $(TESTLOGS)
+summary: $(TESTLOGS)
 	@cat *.testlog > summary
 	@echo "========== Summary =========="
 	@cat summary
 
-%.testlog: %.sh cooja
+%.testlog: %.sh
 	@echo "========== Running script test $(basename $@).sh =========="
 	@bash "$(basename $@).sh" "$(CONTIKI)"
 
 clean:
 	@rm -f *.*log report summary
-
-cooja: $(CONTIKI)/tools/cooja/dist/cooja.jar
-$(CONTIKI)/tools/cooja/dist/cooja.jar:
-	(cd $(CONTIKI)/tools/cooja; ant jar)