diff --git a/src/free-variables.js b/src/free-variables.js
index 837fc4e..e73aeb5 100644
--- a/src/free-variables.js
+++ b/src/free-variables.js
@@ -100,6 +100,7 @@ function freeVariablesInExpression(expression, variables) {
         case 'Literal':
         case 'StringLiteral':
         case 'NumericLiteral':
+        case 'BooleanLiteral':
         case 'JSXEmptyExpression':
             // noop
         break;