diff --git a/onchain/.gitignore b/onchain/.gitignore
index a94c0c9..0fc3309 100644
--- a/onchain/.gitignore
+++ b/onchain/.gitignore
@@ -22,3 +22,8 @@ analysis/profitable_scenario.csv
 fuzzing_results_*
 analysis/fuzz-*.csv
 *.log
+
+# JS package manager lock files (deps managed by forge/foundry, not yarn/npm)
+yarn.lock
+package-lock.json
+node_modules/