diff --git a/lib/compress.js b/lib/compress.js
index cf79b559..3c6dc427 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -94,12 +94,9 @@ function Compressor(options, false_by_default) {
     var global_defs = this.options["global_defs"];
     if (typeof global_defs == "object") for (var key in global_defs) {
         if (/^@/.test(key) && HOP(global_defs, key)) {
-            var ast = parse(global_defs[key]);
-            if (ast.body.length == 1 && ast.body[0] instanceof AST_SimpleStatement) {
-                global_defs[key.slice(1)] = ast.body[0].body;
-            } else throw new Error(string_template("Can't handle expression: {value}", {
-                value: global_defs[key]
-            }));
+            global_defs[key.slice(1)] = parse(global_defs[key], {
+                expression: true
+            });
         }
     }
     var pure_funcs = this.options["pure_funcs"];
@@ -3284,7 +3281,7 @@ merge(Compressor.prototype, {
                 //   https://github.com/mishoo/UglifyJS2/issues/203
                 // if the code argument is a constant, then we can minify it.
                 try {
-                    var code = "NaN(function(" + self.args.slice(0, -1).map(function(arg) {
+                    var code = "n(function(" + self.args.slice(0, -1).map(function(arg) {
                         return arg.value;
                     }).join(",") + "){" + self.args[self.args.length - 1].value + "})";
                     var ast = parse(code);
@@ -3311,18 +3308,18 @@ merge(Compressor.prototype, {
                             })
                         ];
                     }
-                    var args = fun.argnames.map(function(arg, i) {
-                        return make_node(AST_String, self.args[i], {
-                            value: arg.print_to_string()
-                        });
-                    });
                     var code = OutputStream();
                     AST_BlockStatement.prototype._codegen.call(fun, fun, code);
-                    code = code.toString().replace(/^\{|\}$/g, "");
-                    args.push(make_node(AST_String, self.args[self.args.length - 1], {
-                        value: code
-                    }));
-                    self.args = args;
+                    self.args = [
+                        make_node(AST_String, self, {
+                            value: fun.argnames.map(function(arg) {
+                                return arg.print_to_string();
+                            }).join(",")
+                        }),
+                        make_node(AST_String, self.args[self.args.length - 1], {
+                            value: code.get().replace(/^\{|\}$/g, "")
+                        })
+                    ];
                     return self;
                 } catch (ex) {
                     if (ex instanceof JS_Parse_Error) {
diff --git a/package.json b/package.json
index 92f7045f..df480e6e 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "homepage": "https://github.com/mishoo/UglifyJS2/tree/harmony",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.0.20",
+  "version": "3.0.21",
   "engines": {
     "node": ">=0.8.0"
   },
diff --git a/test/compress/functions.js b/test/compress/functions.js
index 065d54db..677c36e8 100644
--- a/test/compress/functions.js
+++ b/test/compress/functions.js
@@ -265,7 +265,7 @@ issue_203: {
     }
     expect: {
         var m = {};
-        var fn = Function("n", "o", "o.exports=42");
+        var fn = Function("n,o", "o.exports=42");
         fn(null, m, m.exports);
         console.log(m.exports);
     }
diff --git a/test/compress/global_defs.js b/test/compress/global_defs.js
index 30c3232f..dd8cd52f 100644
--- a/test/compress/global_defs.js
+++ b/test/compress/global_defs.js
@@ -174,3 +174,24 @@ issue_1986: {
         console.log(42);
     }
 }
+
+issue_2167: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        global_defs: {
+            "@isDevMode": "function(){}",
+        },
+        side_effects: true,
+    }
+    input: {
+        if (isDevMode()) {
+            greetOverlord();
+        }
+        doWork();
+    }
+    expect: {
+        doWork();
+    }
+}
diff --git a/test/compress/issue-203.js b/test/compress/issue-203.js
index c5722273..a9f3dbf9 100644
--- a/test/compress/issue-203.js
+++ b/test/compress/issue-203.js
@@ -8,7 +8,7 @@ compress_new_function: {
         new Function("aa, bb", 'return aa;');
     }
     expect: {
-        Function("n", "r", "return n");
+        Function("n,r", "return n");
     }
 }
 
@@ -27,9 +27,9 @@ compress_new_function_with_destruct: {
         new Function("[[aa]], [{bb}]", 'return aa;');
     }
     expect: {
-        Function("n", "[r]", "return n");
-        Function("n", "{bb:b}", "return n");
-        Function("[[n]]", "[{bb:b}]", "return n");
+        Function("n,[r]", "return n");
+        Function("n,{bb:b}", "return n");
+        Function("[[n]],[{bb:b}]", "return n");
     }
 }
 
@@ -49,8 +49,8 @@ compress_new_function_with_destruct_arrows: {
         new Function("[[aa]], [{bb}]", 'return aa;');
     }
     expect: {
-        Function("N", "[a]", 'return N');
-        Function("b", "{bb:N}", 'return b');
-        Function("[[b]]", "[{bb:N}]", 'return b');
+        Function("n,[a]", "return n");
+        Function("b,{bb:n}", "return b");
+        Function("[[b]],[{bb:n}]", "return b");
     }
 }
diff --git a/test/mocha/minify.js b/test/mocha/minify.js
index 638e79f7..b4722ce2 100644
--- a/test/mocha/minify.js
+++ b/test/mocha/minify.js
@@ -212,7 +212,7 @@ describe("minify", function() {
             });
             var err = result.error;
             assert.ok(err instanceof Error);
-            assert.strictEqual(err.stack.split(/\n/)[0], "Error: Can't handle expression: debugger");
+            assert.strictEqual(err.stack.split(/\n/)[0], "SyntaxError: Unexpected token: keyword (debugger)");
         });
         it("should skip inherited properties", function() {
             var foo = Object.create({ skip: this });