diff --git a/.travis.yml b/.travis.yml
index 620d245..6b6fc86 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,6 +12,9 @@ os:
 
 matrix:
   include:
+  - node_js: 7
+    os: linux
+    env: USE_NPM=true
   - node_js: 6
     os: linux
   - node_js: 4
@@ -19,10 +22,15 @@ matrix:
 
 cache:
   yarn: true
-  directories:
-    - node_modules
 
-script: grunt
+before_install:
+  - if [ "$USE_NPM" == "true" ]; then rm yarn.lock; fi
+
+before_script:
+  - if git status | grep -q "modified.   \.travis\.yml"; then echo "Dirty yarn.lock"; exit 1; fi
+
+script:
+  - grunt
 
 notifications:
   irc:
diff --git a/yarn.lock b/yarn.lock
index 1b9a9f0..96215e5 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2070,9 +2070,9 @@ leaflet-label@^0.2.1-0:
   version "0.2.1-0"
   resolved "https://registry.yarnpkg.com/leaflet-label/-/leaflet-label-0.2.1-0.tgz#b91a678a4d78ac4c47cb230d3926254fd2a7e612"
 
-"leaflet@https://github.com/davojta/Leaflet.git#v0.7.7.1":
-  version "0.7.7.1"
-  resolved "https://github.com/davojta/Leaflet.git#57c85cbf0f1e495bce4f1a11be26766b48c08cbc"
+"leaflet@https://github.com/davojta/Leaflet.git#stable_0_7_7_1_release":
+  version "0.7.7"
+  resolved "https://github.com/davojta/Leaflet.git#bf3bcd089bea98d3f75bda08a79d8260f27eb3bf"
 
 levn@^0.3.0, levn@~0.3.0:
   version "0.3.0"