diff --git a/crates/swc/src/lib.rs b/crates/swc/src/lib.rs
index 11f05df89cf0..95f01b178f0e 100644
--- a/crates/swc/src/lib.rs
+++ b/crates/swc/src/lib.rs
@@ -1006,7 +1006,11 @@ impl Compiler {
                         .with_emit_assert_for_import_attributes(
                             config.emit_assert_for_import_attributes,
                         ),
-                    output: Some(output),
+                    output: if output.is_empty() {
+                        None
+                    } else {
+                        Some(output)
+                    },
                 },
             )
         })
diff --git a/crates/swc/tests/fixture/issues-9xxx/9015/input/.swcrc b/crates/swc/tests/fixture/issues-9xxx/9015/input/.swcrc
new file mode 100644
index 000000000000..0b625e989920
--- /dev/null
+++ b/crates/swc/tests/fixture/issues-9xxx/9015/input/.swcrc
@@ -0,0 +1,19 @@
+{
+    "jsc": {
+        "parser": {
+            "syntax": "ecmascript",
+            "jsx": false
+        },
+        "target": "es2015",
+        "loose": false,
+        "minify": {
+            "compress": false,
+            "mangle": true
+        }
+    },
+    "module": {
+        "type": "es6"
+    },
+    "minify": true,
+    "isModule": false
+}
\ No newline at end of file
diff --git a/crates/swc/tests/fixture/issues-9xxx/9015/input/1.js b/crates/swc/tests/fixture/issues-9xxx/9015/input/1.js
new file mode 100644
index 000000000000..7fd21cbb53ad
--- /dev/null
+++ b/crates/swc/tests/fixture/issues-9xxx/9015/input/1.js
@@ -0,0 +1 @@
+register(function duplicate_func(duplicate_param, offset = 0) { })
diff --git a/crates/swc/tests/fixture/issues-9xxx/9015/output/1.js b/crates/swc/tests/fixture/issues-9xxx/9015/output/1.js
new file mode 100644
index 000000000000..88d474b91428
--- /dev/null
+++ b/crates/swc/tests/fixture/issues-9xxx/9015/output/1.js
@@ -0,0 +1 @@
+register(function e(i,n=0){});
diff --git a/crates/swc/tests/tsc-references/parameterInitializersForwardReferencing.2(target=es2015).1.normal.js b/crates/swc/tests/tsc-references/parameterInitializersForwardReferencing.2(target=es2015).1.normal.js
index c9a59d368b27..273e67f9d735 100644
--- a/crates/swc/tests/tsc-references/parameterInitializersForwardReferencing.2(target=es2015).1.normal.js
+++ b/crates/swc/tests/tsc-references/parameterInitializersForwardReferencing.2(target=es2015).1.normal.js
@@ -3,14 +3,14 @@
 import { _ as _object_without_properties } from "@swc/helpers/_/_object_without_properties";
 function a() {}
 function b(_param = a()) {
-    var { b = a() } = _param, x = _object_without_properties(_param, [
+    var { b: b1 = a() } = _param, x = _object_without_properties(_param, [
         "b"
     ]);
     var a1;
 }
 const x = "";
 function c(_param = a(), d = x) {
-    var { b } = _param, c = _object_without_properties(_param, [
+    var { b } = _param, c1 = _object_without_properties(_param, [
         "b"
     ]);
     var x1;
diff --git a/crates/swc/tests/tsc-references/parameterInitializersForwardReferencing.2(target=esnext).1.normal.js b/crates/swc/tests/tsc-references/parameterInitializersForwardReferencing.2(target=esnext).1.normal.js
index ca6a5a52a09d..3ce65475ccc6 100644
--- a/crates/swc/tests/tsc-references/parameterInitializersForwardReferencing.2(target=esnext).1.normal.js
+++ b/crates/swc/tests/tsc-references/parameterInitializersForwardReferencing.2(target=esnext).1.normal.js
@@ -1,10 +1,10 @@
 //// [parameterInitializersForwardReferencing.2.ts]
 // https://github.com/microsoft/TypeScript/issues/36295
 function a() {}
-function b({ b = a(), ...x } = a()) {
+function b({ b: b1 = a(), ...x } = a()) {
     var a1;
 }
 const x = "";
-function c({ b, ...c } = a(), d = x) {
+function c({ b, ...c1 } = a(), d = x) {
     var x1;
 }
diff --git a/crates/swc_ecma_minifier/tests/benches-full/victory.js b/crates/swc_ecma_minifier/tests/benches-full/victory.js
index 604359246992..70bbc01bcfc4 100644
--- a/crates/swc_ecma_minifier/tests/benches-full/victory.js
+++ b/crates/swc_ecma_minifier/tests/benches-full/victory.js
@@ -25189,10 +25189,10 @@
             "use strict";
             function pairs(values, pairof = pair) {
                 let previous;
-                const pairs = [];
+                const pairs1 = [];
                 let first = !1;
-                for (const value of values)first && pairs.push(pairof(previous, value)), previous = value, first = !0;
-                return pairs;
+                for (const value of values)first && pairs1.push(pairof(previous, value)), previous = value, first = !0;
+                return pairs1;
             }
             function pair(a, b) {
                 return [
diff --git a/crates/swc_ecma_minifier/tests/fixture/next/36127/2/3/output.js b/crates/swc_ecma_minifier/tests/fixture/next/36127/2/3/output.js
index 4c1bad4d5f39..fb88c8b8d87b 100644
--- a/crates/swc_ecma_minifier/tests/fixture/next/36127/2/3/output.js
+++ b/crates/swc_ecma_minifier/tests/fixture/next/36127/2/3/output.js
@@ -204,10 +204,10 @@ class e extends Text {
         return a(), 1 == o.length ? o[0] : new e(o, i);
     }
 }
-function n(t, e, n = 0, i = 1e9) {
-    for(let s = 0, h = 0, l = !0; h < t.length && s <= i; h++){
-        let r = t[h], o = s + r.length;
-        o >= n && (o > i && (r = r.slice(0, i - s)), s < n && (r = r.slice(n - s)), l ? (e[e.length - 1] += r, l = !1) : e.push(r)), s = o + 1;
+function n(t, e, i = 0, s = 1e9) {
+    for(let n = 0, h = 0, l = !0; h < t.length && n <= s; h++){
+        let r = t[h], o = n + r.length;
+        o >= i && (o > s && (r = r.slice(0, s - n)), n < i && (r = r.slice(i - n)), l ? (e[e.length - 1] += r, l = !1) : e.push(r)), n = o + 1;
     }
     return e;
 }
diff --git a/crates/swc_ecma_minifier/tests/mangle/1/output.js b/crates/swc_ecma_minifier/tests/mangle/1/output.js
index ce5f57a786ad..a5b875322e32 100644
--- a/crates/swc_ecma_minifier/tests/mangle/1/output.js
+++ b/crates/swc_ecma_minifier/tests/mangle/1/output.js
@@ -9,7 +9,7 @@ Object.defineProperty(exports, "__esModule", {
 });
 const e = t(require("./config.json"));
 function n({ config: t = e.default } = {}) {
-    function n(e) {
+    function r(e) {
         const n = t[e] || null;
         if (!n) {
             return false;
@@ -20,13 +20,13 @@ function n({ config: t = e.default } = {}) {
         }
         return Date.now() >= u && r;
     }
-    function r(e) {
+    function u(e) {
         const n = t[e] || null;
         return n;
     }
     return {
-        longlong10: r,
-        longlong2: n,
+        longlong10: u,
+        longlong2: r,
         longlong100: t
     };
 }
diff --git a/crates/swc_ecma_minifier/tests/mangle/reuse/2/output.js b/crates/swc_ecma_minifier/tests/mangle/reuse/2/output.js
index b71439b432d0..99756cdda264 100644
--- a/crates/swc_ecma_minifier/tests/mangle/reuse/2/output.js
+++ b/crates/swc_ecma_minifier/tests/mangle/reuse/2/output.js
@@ -1,8 +1,8 @@
-function e(e, t = {}, n = false) {
+function e(t, n = {}, r = false) {
     return {
-        rule: e,
-        params: t,
-        implicit: n
+        rule: t,
+        params: n,
+        implicit: r
     };
 }
 function t(t) {
diff --git a/crates/swc_ecma_minifier/tests/terser/compress/destructuring/issue_3205_3/output.mangleOnly.js b/crates/swc_ecma_minifier/tests/terser/compress/destructuring/issue_3205_3/output.mangleOnly.js
index 75124db198cd..f10ff2f31424 100644
--- a/crates/swc_ecma_minifier/tests/terser/compress/destructuring/issue_3205_3/output.mangleOnly.js
+++ b/crates/swc_ecma_minifier/tests/terser/compress/destructuring/issue_3205_3/output.mangleOnly.js
@@ -1,6 +1,6 @@
 (function() {
-    function n(n, { a: o  } = n) {
-        console.log(o);
+    function n(o, { a: c } = o) {
+        console.log(c);
     }
     n({
         a: "PASS"
diff --git a/crates/swc_ecma_minifier/tests/terser/compress/harmony/default_assign/output.mangleOnly.js b/crates/swc_ecma_minifier/tests/terser/compress/harmony/default_assign/output.mangleOnly.js
index b05976810529..c07c998c16be 100644
--- a/crates/swc_ecma_minifier/tests/terser/compress/harmony/default_assign/output.mangleOnly.js
+++ b/crates/swc_ecma_minifier/tests/terser/compress/harmony/default_assign/output.mangleOnly.js
@@ -1,5 +1,5 @@
-function o(o, n = 3) {
-    console.log(o);
+function o(n, c = 3) {
+    console.log(n);
 }
 g = ([[] = 123])=>{};
 h = ([[o, n, c] = [
@@ -7,7 +7,7 @@ h = ([[o, n, c] = [
     5,
     6
 ]] = [])=>{};
-function n([[o, n, c] = [
+function n([[o, c, l] = [
     4,
     5,
     6
diff --git a/crates/swc_ecma_minifier/tests/terser/compress/harmony/issue_t80/output.mangleOnly.js b/crates/swc_ecma_minifier/tests/terser/compress/harmony/issue_t80/output.mangleOnly.js
index 0df4b7bdfac7..d0ad925860b9 100644
--- a/crates/swc_ecma_minifier/tests/terser/compress/harmony/issue_t80/output.mangleOnly.js
+++ b/crates/swc_ecma_minifier/tests/terser/compress/harmony/issue_t80/output.mangleOnly.js
@@ -1,11 +1,11 @@
-function n(n = []) {
-    var l, u = "unused";
+function n(l = []) {
+    var u, e = "unused";
     if (arguments.length == 1) {
-        n = [
-            n
+        l = [
+            l
         ];
     }
-    return n;
+    return l;
 }
 console.log(JSON.stringify([
     n(),
diff --git a/crates/swc_ecma_minifier/tests/terser/compress/issue_1043/issue_1043/output.mangleOnly.js b/crates/swc_ecma_minifier/tests/terser/compress/issue_1043/issue_1043/output.mangleOnly.js
index 2401cd065d18..abdc6efc53de 100644
--- a/crates/swc_ecma_minifier/tests/terser/compress/issue_1043/issue_1043/output.mangleOnly.js
+++ b/crates/swc_ecma_minifier/tests/terser/compress/issue_1043/issue_1043/output.mangleOnly.js
@@ -1,9 +1,9 @@
-function* l(l = 0, n = null, f = 1) {
-    if (n == null) {
-        n = l;
-        l = 0;
+function* l(n = 0, f = null, i = 1) {
+    if (f == null) {
+        f = n;
+        n = 0;
     }
-    for(let i = l; i < n; i += f){
-        yield i;
+    for(let l = n; l < f; l += i){
+        yield l;
     }
 }
diff --git a/crates/swc_ecma_minifier/tests/terser/compress/parameters/default_arguments/output.mangleOnly.js b/crates/swc_ecma_minifier/tests/terser/compress/parameters/default_arguments/output.mangleOnly.js
index 9d2d8cdd9366..f7358efb607f 100644
--- a/crates/swc_ecma_minifier/tests/terser/compress/parameters/default_arguments/output.mangleOnly.js
+++ b/crates/swc_ecma_minifier/tests/terser/compress/parameters/default_arguments/output.mangleOnly.js
@@ -1,5 +1,5 @@
-function n(n = 6) {}
-function n(n = 6 + 5) {}
-function n({ foo: n  } = {}, [c] = [
+function n(c = 6) {}
+function n(c = 6 + 5) {}
+function n({ foo: c } = {}, [f] = [
     1
 ]) {}
diff --git a/crates/swc_ecma_transforms_base/src/rename/analyzer/mod.rs b/crates/swc_ecma_transforms_base/src/rename/analyzer/mod.rs
index 9c26d5cc4c25..bb7f5ad429ac 100644
--- a/crates/swc_ecma_transforms_base/src/rename/analyzer/mod.rs
+++ b/crates/swc_ecma_transforms_base/src/rename/analyzer/mod.rs
@@ -250,7 +250,14 @@ impl Visit for Analyzer {
         self.add_decl(f.ident.to_id(), true);
 
         // https://github.com/swc-project/swc/issues/6819
-        let has_rest = f.function.params.iter().any(|p| p.pat.is_rest());
+        //
+        // We need to check for assign pattern because safari has a bug.
+        // https://github.com/swc-project/swc/issues/9015
+        let has_rest = f
+            .function
+            .params
+            .iter()
+            .any(|p| p.pat.is_rest() || p.pat.is_assign());
         if has_rest {
             self.add_usage(f.ident.to_id());
         }
@@ -274,7 +281,14 @@ impl Visit for Analyzer {
                 v.add_decl(id.to_id(), true);
                 v.with_fn_scope(|v| {
                     // https://github.com/swc-project/swc/issues/6819
-                    if f.function.params.iter().any(|p| p.pat.is_rest()) {
+                    //
+                    // We need to check for assign pattern because safari has a bug.
+                    // https://github.com/swc-project/swc/issues/9015
+                    if f.function
+                        .params
+                        .iter()
+                        .any(|p| p.pat.is_rest() || p.pat.is_assign())
+                    {
                         v.add_usage(id.to_id());
                     }