diff --git a/index.js b/index.js
index 8c07188..80cff2a 100755
--- a/index.js
+++ b/index.js
@@ -196,9 +196,16 @@ function merge (argv) {
     'git',
     ['merge-file', '-p', argv['%A'], argv['%O'], argv['%B']],
     {
-      stdio: [0, 'pipe', 2]
+      stdio: [0, 'pipe', 2],
+      maxBuffer: Infinity
     }
   )
+
+  if (ret.error) {
+    console.error('npm-merge-driver: "git merge-file" fails with:', ret.error)
+    throw ret.error
+  }
+
   fs.writeFileSync(argv['%P'], ret.stdout)
   try {
     cp.execSync(argv.command, {