diff --git a/package.json b/package.json
index f727b67b..92f30df7 100755
--- a/package.json
+++ b/package.json
@@ -24,8 +24,8 @@
     "test": "VIPS_WARNING=0 node ./node_modules/istanbul/lib/cli.js cover ./node_modules/mocha/bin/_mocha -- --slow=5000 --timeout=20000 ./test/unit/*.js",
     "test-clean": "npm run clean && npm install && npm test",
     "test-leak": "cd test/leak; ./leak.sh; cd - > /dev/null",
-    "test-win32-node": "node ./node_modules/mocha/bin/mocha --slow=5000 --timeout=20000 ./test/unit/*.js",
-    "test-win32-iojs": "iojs ./node_modules/mocha/bin/mocha --slow=5000 --timeout=20000 ./test/unit/*.js"
+    "test-win32-node": "node ./node_modules/mocha/bin/mocha --slow=5000 --timeout=30000 ./test/unit/*.js",
+    "test-win32-iojs": "iojs ./node_modules/mocha/bin/mocha --slow=5000 --timeout=30000 ./test/unit/*.js"
   },
   "main": "index.js",
   "repository": {