diff --git a/lib/compress.js b/lib/compress.js
index ab552c67..596b03fa 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -277,7 +277,7 @@ merge(Compressor.prototype, {
                 }
                 if (node instanceof AST_VarDef) {
                     var d = node.name.definition();
-                    if (safe_to_assign(d, node.value)) {
+                    if (d.fixed === undefined || safe_to_assign(d, node.value)) {
                         if (node.value) {
                             d.fixed = function() {
                                 return node.value;
@@ -297,9 +297,7 @@ merge(Compressor.prototype, {
                     && node.operator == "="
                     && node.left instanceof AST_SymbolRef) {
                     var d = node.left.definition();
-                    if (HOP(safe_ids, d.id)
-                        && safe_to_read(d)
-                        && safe_to_assign(d, node.right)) {
+                    if (safe_to_assign(d, node.right)) {
                         d.references.push(node.left);
                         d.fixed = function() {
                             return node.right;
@@ -325,6 +323,7 @@ merge(Compressor.prototype, {
                     return true;
                 }
                 if (node instanceof AST_Function) {
+                    push();
                     var iife;
                     if (!node.name
                         && (iife = tw.parent()) instanceof AST_Call
@@ -340,7 +339,6 @@ merge(Compressor.prototype, {
                             mark(d, true);
                         });
                     }
-                    push();
                     descend();
                     pop();
                     return true;
@@ -451,7 +449,8 @@ merge(Compressor.prototype, {
         }
 
         function safe_to_assign(def, value) {
-            if (def.fixed === undefined) return true;
+            if (!HOP(safe_ids, def.id)) return false;
+            if (!safe_to_read(def)) return false;
             if (def.fixed === false) return false;
             if (def.fixed != null && (!value || def.references.length > 0)) return false;
             return !def.orig.some(function(sym) {
diff --git a/test/compress/reduce_vars.js b/test/compress/reduce_vars.js
index 5a68e79b..c5f26904 100644
--- a/test/compress/reduce_vars.js
+++ b/test/compress/reduce_vars.js
@@ -571,7 +571,7 @@ inner_var_label: {
     }
 }
 
-inner_var_for: {
+inner_var_for_1: {
     options = {
         evaluate: true,
         reduce_vars: true,
@@ -600,6 +600,29 @@ inner_var_for: {
     }
 }
 
+inner_var_for_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function() {
+            var a = 1;
+            for (var b = 1; --b;) var a = 2;
+            console.log(a);
+        }();
+    }
+    expect: {
+        !function() {
+            a = 1;
+            for (var b = 1; --b;) var a = 2;
+            console.log(a);
+        }();
+    }
+    expect_stdout: "1"
+}
+
 inner_var_for_in_1: {
     options = {
         evaluate: true,