diff --git a/build.sh b/build.sh
index 95e9e2bd3d486..194a322cd570f 100755
--- a/build.sh
+++ b/build.sh
@@ -45,7 +45,6 @@ while [[ "${1:-}" != "" ]]; do
     shift
 done
 
-export PATH=$(npm bin):$PATH
 export NODE_OPTIONS="--max-old-space-size=8196 --experimental-worker ${NODE_OPTIONS:-}"
 
 # Temporary log memory for long builds (this may mess with tests that check stderr)
diff --git a/scripts/gen.sh b/scripts/gen.sh
index 9da7dd5cf5997..b317366b9452d 100755
--- a/scripts/gen.sh
+++ b/scripts/gen.sh
@@ -1,7 +1,6 @@
 #!/bin/bash
 set -euo pipefail
 
-export PATH=$(npm bin):$PATH
 export NODE_OPTIONS="--max-old-space-size=8196 ${NODE_OPTIONS:-}"
 
 echo "============================================================================================="
@@ -15,8 +14,8 @@ fail() {
 
 echo "============================================================================================="
 echo "building required build tools..."
-time lerna run --stream build --scope @aws-cdk/cfn2ts --scope @aws-cdk/ubergen --include-dependencies || fail
+time npx lerna run --stream build --scope @aws-cdk/cfn2ts --scope @aws-cdk/ubergen --include-dependencies || fail
 
 echo "============================================================================================="
 echo "executing gen..."
-time lerna run --stream gen || fail
+time npx lerna run --stream gen || fail