diff --git a/ml.cpp b/ml.cpp
index 490d782..b2efb51 100644
--- a/ml.cpp
+++ b/ml.cpp
@@ -111,12 +111,12 @@ MlValue::MlValue(const std::vector<MlValue> &params, MlValue ret, MlEnvironment
 	list.push_back(ret);
 
 //	// Lambdas capture only variables that they know they will use.
-//	std::vector<std::string> used_atoms = ret.get_used_atoms();
-//	for (size_t i = 0; i < used_atoms.size(); i++) {
-//		// If the environment has a symbol that this lambda uses, capture it.
-//		if (env.has(used_atoms[i]))
-//			lambda_scope.set(used_atoms[i], env.get(used_atoms[i]));
-//	}
+	std::vector<std::string> used_atoms = ret.get_used_atoms();
+	for (size_t i = 0; i < used_atoms.size(); i++) {
+		// If the environment has a symbol that this lambda uses, capture it.
+		if (env.has(used_atoms[i]))
+			lambda_scope.set(used_atoms[i], env.get(used_atoms[i]));
+	}
 }
 
 // Construct a builtin function