diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1b6bc66cc2..81891ce2db 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,11 @@
 
 _Note: Gaps between patch versions are faulty/broken releases._
 
+## 2.12.2
+
+ * **Internal**
+  * Exclude nodes in function parameters and catch clauses from `isReferenced` check.
+
 ## 2.12.1
 
  * **Internal**
diff --git a/lib/6to5/types/index.js b/lib/6to5/types/index.js
index ef433cd5b1..99308880ad 100644
--- a/lib/6to5/types/index.js
+++ b/lib/6to5/types/index.js
@@ -193,6 +193,17 @@ t.isReferenced = function (node, parent) {
   // we're a property key and we aren't computed so we aren't referenced
   if (t.isProperty(parent) && parent.key === node && !parent.computed) return false;
 
+  if (t.isFunction(parent)) {
+    // we're a function param
+    if (_.contains(parent.params, node)) return false;
+
+    // we're a rest parameter
+    if (_.contains(parent.params, node)) return false;
+  }
+
+  // we're a catch clause param
+  if (t.isCatchClause(parent) && parent.param === node) return false;
+
   // we're a variable declarator id so we aren't referenced
   if (t.isVariableDeclarator(parent) && parent.id === node) return false;