diff --git a/packages/test/e2e.sh b/packages/test/e2e.sh
index 776b4c3..8b90c82 100644
--- a/packages/test/e2e.sh
+++ b/packages/test/e2e.sh
@@ -96,14 +96,14 @@ function createTmpFixture() {
   echo "FIXTURE: $1"
   echo "TEMP: $TEMP";
   echo "PWD: $(pwd)";
-  npm install --legacy-peer-deps > /dev/null;
+  yarn install --registry "$LOCAL_REGISTRY_URL" > /dev/null;
 }
 
 # webpack-dev-server
 
 createTmpFixture webpack-dev-server/basic;
-npm install @ssen/webpack-dev-server@e2e --legacy-peer-deps --save-dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
-(PORT=$TEST_SERVER_PORT npm run start &> log.txt &);
+yarn add @ssen/webpack-dev-server@e2e --dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
+(PORT=$TEST_SERVER_PORT yarn run start &> log.txt &);
 sleep 15s;
 is200 "http://localhost:$TEST_SERVER_PORT";
 stopTestServer;
@@ -111,16 +111,16 @@ stopTestServer;
 # web
 
 createTmpFixture web/start;
-npm install @rocket-scripts/web@e2e --legacy-peer-deps --save-dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
+yarn add @rocket-scripts/web@e2e --dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
 
-(PORT=$TEST_SERVER_PORT npm run start &> log.txt &);
+(PORT=$TEST_SERVER_PORT yarn run start &> log.txt &);
 sleep 15s;
 is200 "http://localhost:$TEST_SERVER_PORT";
 is200 "http://localhost:$TEST_SERVER_PORT/manifest.json";
 is200 "http://localhost:$TEST_SERVER_PORT/favicon.ico";
 stopTestServer;
 
-npm run build;
+yarn run build;
 fileExists "$TEMP"/out/app/manifest.json;
 fileExists "$TEMP"/out/app/size-report.html;
 fileExists "$TEMP"/out/app/favicon.ico;
@@ -130,9 +130,9 @@ fileExists "$TEMP"/out/app/vendor.*.js;
 
 
 createTmpFixture web/worker;
-npm install @rocket-scripts/web@e2e --legacy-peer-deps --save-dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
+yarn add @rocket-scripts/web@e2e --dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
 
-npm run build;
+yarn run build;
 fileExists "$TEMP"/out/app/manifest.json;
 fileExists "$TEMP"/out/app/size-report.html;
 fileExists "$TEMP"/out/app/favicon.ico;
@@ -143,16 +143,16 @@ fileExists "$TEMP"/out/app/*.worker.js;
 
 
 createTmpFixture web/webpack-config;
-npm install @rocket-scripts/web@e2e --legacy-peer-deps --save-dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
+yarn add @rocket-scripts/web@e2e --dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
 
-(PORT=$TEST_SERVER_PORT npm run start &> log.txt &);
+(PORT=$TEST_SERVER_PORT yarn run start &> log.txt &);
 sleep 15s;
 is200 "http://localhost:$TEST_SERVER_PORT";
 is200 "http://localhost:$TEST_SERVER_PORT/manifest.json";
 is200 "http://localhost:$TEST_SERVER_PORT/favicon.ico";
 stopTestServer;
 
-npm run build;
+yarn run build;
 fileExists "$TEMP"/out/app/manifest.json;
 fileExists "$TEMP"/out/app/size-report.html;
 fileExists "$TEMP"/out/app/favicon.ico;
@@ -161,9 +161,9 @@ fileExists "$TEMP"/out/app/index.html;
 
 
 createTmpFixture web/static-file-directories;
-npm install @rocket-scripts/web@e2e --legacy-peer-deps --save-dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
+yarn add @rocket-scripts/web@e2e --dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
 
-(PORT=$TEST_SERVER_PORT npm run start &> log.txt &);
+(PORT=$TEST_SERVER_PORT yarn run start &> log.txt &);
 sleep 15s;
 is200 "http://localhost:$TEST_SERVER_PORT";
 is200 "http://localhost:$TEST_SERVER_PORT/manifest.json";
@@ -171,7 +171,7 @@ is200 "http://localhost:$TEST_SERVER_PORT/favicon.ico";
 is200 "http://localhost:$TEST_SERVER_PORT/hello.json";
 stopTestServer;
 
-npm run build;
+yarn run build;
 fileExists "$TEMP"/out/app/manifest.json;
 fileExists "$TEMP"/out/app/size-report.html;
 fileExists "$TEMP"/out/app/favicon.ico;
@@ -181,9 +181,9 @@ fileExists "$TEMP"/out/app/hello.json;
 
 
 createTmpFixture web/proxy;
-npm install @rocket-scripts/web@e2e --legacy-peer-deps --save-dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
+yarn add @rocket-scripts/web@e2e --dev --registry "$LOCAL_REGISTRY_URL" > /dev/null;
 
-(PORT=$TEST_SERVER_PORT npm run start &> log.txt &);
+(PORT=$TEST_SERVER_PORT yarn run start &> log.txt &);
 sleep 15s;
 is200 "http://localhost:$TEST_SERVER_PORT";
 is200 "http://localhost:$TEST_SERVER_PORT/manifest.json";