diff --git a/lib/minify.js b/lib/minify.js
index c112a17d4..aa3f73d83 100644
--- a/lib/minify.js
+++ b/lib/minify.js
@@ -297,18 +297,15 @@ async function minify(files, options, _fs_module) {
         }
 
         if (options.sourceMap) {
+            if (options.sourceMap.includeSources && files instanceof AST_Toplevel) {
+                throw new Error("original source content unavailable");
+            }
             options.format.source_map = await SourceMap({
                 file: options.sourceMap.filename,
                 orig: options.sourceMap.content,
-                root: options.sourceMap.root
+                root: options.sourceMap.root,
+                files: options.sourceMap.includeSources ? files : null,
             });
-            if (options.sourceMap.includeSources) {
-                if (files instanceof AST_Toplevel) {
-                    throw new Error("original source content unavailable");
-                } else for (var name in files) if (HOP(files, name)) {
-                    options.format.source_map.get().setSourceContent(name, files[name]);
-                }
-            }
         }
         delete options.format.ast;
         delete options.format.code;
@@ -317,11 +314,21 @@ async function minify(files, options, _fs_module) {
         toplevel.print(stream);
         result.code = stream.get();
         if (options.sourceMap) {
-            if(options.sourceMap.asObject) {
-                result.map = options.format.source_map.get().toJSON();
-            } else {
-                result.map = options.format.source_map.toString();
-            }
+            Object.defineProperty(result, "map", {
+                configurable: true,
+                enumerable: true,
+                get() {
+                    const map = options.format.source_map.getEncoded();
+                    return (result.map = options.sourceMap.asObject ? map : JSON.stringify(map));
+                },
+                set(value) {
+                    Object.defineProperty(result, "map", {
+                        value,
+                        writable: true,
+                    });
+                }
+            });
+            result.decoded_map = options.format.source_map.getDecoded();
             if (options.sourceMap.url == "inline") {
                 var sourceMap = typeof result.map === "object" ? JSON.stringify(result.map) : result.map;
                 result.code += "\n//# sourceMappingURL=data:application/json;charset=utf-8;base64," + to_base64(sourceMap);
diff --git a/lib/sourcemap.js b/lib/sourcemap.js
index 598babce6..34bdd0605 100644
--- a/lib/sourcemap.js
+++ b/lib/sourcemap.js
@@ -43,34 +43,39 @@
 
 "use strict";
 
-import MOZ_SourceMap from "source-map";
-import {AnyMap, originalPositionFor} from "@jridgewell/trace-mapping";
-import {defaults} from "./utils/index.js";
+import {SourceMapConsumer, SourceMapGenerator} from "@jridgewell/source-map";
+import {defaults, HOP} from "./utils/index.js";
 
-// a small wrapper around source-map and @jridgewell/trace-mapping
-function SourceMap(options) {
+// a small wrapper around source-map and @jridgewell/source-map
+async function SourceMap(options) {
     options = defaults(options, {
         file : null,
         root : null,
         orig : null,
-
-        orig_line_diff : 0,
-        dest_line_diff : 0,
+        files: {},
     });
 
     var orig_map;
-    var generator = new MOZ_SourceMap.SourceMapGenerator({
+    var generator = new SourceMapGenerator({
         file       : options.file,
         sourceRoot : options.root
     });
 
+    let sourcesContent = {__proto__: null};
+    let files = options.files;
+    for (var name in files) if (HOP(files, name)) {
+        sourcesContent[name] = files[name];
+    }
     if (options.orig) {
-        orig_map = new AnyMap(options.orig);
+        // We support both @jridgewell/source-map (which has a sync
+        // SourceMapConsumer) and source-map (which has an async
+        // SourceMapConsumer).
+        orig_map = await new SourceMapConsumer(options.orig);
         if (orig_map.sourcesContent) {
-            orig_map.resolvedSources.forEach(function(source, i) {
-                var sourceContent = orig_map.sourcesContent[i];
-                if (sourceContent) {
-                    generator.setSourceContent(source, sourceContent);
+            orig_map.sources.forEach(function(source, i) {
+                var content = orig_map.sourcesContent[i];
+                if (content) {
+                    sourcesContent[source] = content;
                 }
             });
         }
@@ -78,7 +83,7 @@ function SourceMap(options) {
 
     function add(source, gen_line, gen_col, orig_line, orig_col, name) {
         if (orig_map) {
-            var info = originalPositionFor(orig_map, {
+            var info = orig_map.originalPositionFor({
                 line: orig_line,
                 column: orig_col
             });
@@ -91,18 +96,42 @@ function SourceMap(options) {
             name = info.name || name;
         }
         generator.addMapping({
-            generated : { line: gen_line + options.dest_line_diff, column: gen_col },
-            original  : { line: orig_line + options.orig_line_diff, column: orig_col },
+            generated : { line: gen_line, column: gen_col },
+            original  : { line: orig_line, column: orig_col },
             source    : source,
             name      : name
         });
+        generator.setSourceContent(source, sourcesContent[source]);
+    }
+
+    function clean(map) {
+        const allNull = map.sourcesContent && map.sourcesContent.every(c => c == null);
+        if (allNull) delete map.sourcesContent;
+        if (map.file === undefined) delete map.file;
+        if (map.sourceRoot === undefined) delete map.sourceRoot;
+        return map;
+    }
+
+    function getDecoded() {
+        if (!generator.toDecodedMap) return null;
+        return clean(generator.toDecodedMap());
+    }
+
+    function getEncoded() {
+        return clean(generator.toJSON());
+    }
+
+    function destroy() {
+        // @jridgewell/source-map's SourceMapConsumer does not need to be
+        // manually freed.
+        if (orig_map && orig_map.destroy) orig_map.destroy();
     }
 
     return {
-        add        : add,
-        get        : function() { return generator; },
-        toString   : function() { return generator.toString(); },
-        destroy    : function() {}
+        add,
+        getDecoded,
+        getEncoded,
+        destroy,
     };
 }
 
diff --git a/package-lock.json b/package-lock.json
index 46ee7e167..08594d68e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -83,10 +83,34 @@
       "integrity": "sha512-wdppn25U8z/2yiaT6YGquE6X8sSv7hNMWSXYSSU1jGv/yd6XqjXgTDJ8KP4NgjTXfJ3GbRjeeb8RTV7a/VpM+w==",
       "dev": true
     },
+    "@jridgewell/gen-mapping": {
+      "version": "0.3.0",
+      "resolved": "https://registry.npmjs.org/@jridgewell/gen-mapping/-/gen-mapping-0.3.0.tgz",
+      "integrity": "sha512-bFDbLEZ84DtNwXILbufXeQMz3tcGSfy+ROgvnB9jUm+t48G4Po+1UhhyFh6GIsFOE2R31Ab0ddeMv+Z9gcYC4g==",
+      "requires": {
+        "@jridgewell/set-array": "^1.0.0",
+        "@jridgewell/sourcemap-codec": "^1.4.10",
+        "@jridgewell/trace-mapping": "^0.3.9"
+      }
+    },
     "@jridgewell/resolve-uri": {
-      "version": "3.0.5",
-      "resolved": "https://registry.npmjs.org/@jridgewell/resolve-uri/-/resolve-uri-3.0.5.tgz",
-      "integrity": "sha512-VPeQ7+wH0itvQxnG+lIzWgkysKIr3L9sslimFW55rHMdGu/qCQ5z5h9zq4gI8uBtqkpHhsF4Z/OwExufUCThew=="
+      "version": "3.0.6",
+      "resolved": "https://registry.npmjs.org/@jridgewell/resolve-uri/-/resolve-uri-3.0.6.tgz",
+      "integrity": "sha512-R7xHtBSNm+9SyvpJkdQl+qrM3Hm2fea3Ef197M3mUug+v+yR+Rhfbs7PBtcBUVnIWJ4JcAdjvij+c8hXS9p5aw=="
+    },
+    "@jridgewell/set-array": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/@jridgewell/set-array/-/set-array-1.1.0.tgz",
+      "integrity": "sha512-SfJxIxNVYLTsKwzB3MoOQ1yxf4w/E6MdkvTgrgAt1bfxjSrLUoHMKrDOykwN14q65waezZIdqDneUIPh4/sKxg=="
+    },
+    "@jridgewell/source-map": {
+      "version": "0.3.2",
+      "resolved": "https://registry.npmjs.org/@jridgewell/source-map/-/source-map-0.3.2.tgz",
+      "integrity": "sha512-m7O9o2uR8k2ObDysZYzdfhb08VuEml5oWGiosa1VdaPZ/A6QyPkAJuwN0Q1lhULOf6B7MtQmHENS743hWtCrgw==",
+      "requires": {
+        "@jridgewell/gen-mapping": "^0.3.0",
+        "@jridgewell/trace-mapping": "^0.3.9"
+      }
     },
     "@jridgewell/sourcemap-codec": {
       "version": "1.4.11",
@@ -94,9 +118,9 @@
       "integrity": "sha512-Fg32GrJo61m+VqYSdRSjRXMjQ06j8YIYfcTqndLYVAaHmroZHLJZCydsWBOTDqXS2v+mjxohBWEMfg97GXmYQg=="
     },
     "@jridgewell/trace-mapping": {
-      "version": "0.3.5",
-      "resolved": "https://registry.npmjs.org/@jridgewell/trace-mapping/-/trace-mapping-0.3.5.tgz",
-      "integrity": "sha512-JVOWdxPmgNsrNKVyhFNB08go/kCnXUT5m3Ds11F3lh3oKzCHTzs3IHRC9VI0t8mNyL4TfypxTiwQPU+77Sfm6g==",
+      "version": "0.3.9",
+      "resolved": "https://registry.npmjs.org/@jridgewell/trace-mapping/-/trace-mapping-0.3.9.tgz",
+      "integrity": "sha512-3Belt6tdc8bPgAtbcmdtNJlirVoTmEb5e2gC94PnkwEW9jI6CAHUeoG85tjWP5WquqfavoMtMwiG4P926ZKKuQ==",
       "requires": {
         "@jridgewell/resolve-uri": "^3.0.3",
         "@jridgewell/sourcemap-codec": "^1.4.10"
@@ -934,7 +958,8 @@
     "lodash.sortby": {
       "version": "4.7.0",
       "resolved": "https://registry.npmjs.org/lodash.sortby/-/lodash.sortby-4.7.0.tgz",
-      "integrity": "sha1-7dFMgk4sycHgsKG0K7UhBRakJDg="
+      "integrity": "sha1-7dFMgk4sycHgsKG0K7UhBRakJDg=",
+      "dev": true
     },
     "lodash.truncate": {
       "version": "4.4.2",
@@ -1270,7 +1295,8 @@
     "punycode": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.1.1.tgz",
-      "integrity": "sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A=="
+      "integrity": "sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A==",
+      "dev": true
     },
     "random-int": {
       "version": "2.0.1",
@@ -1513,6 +1539,7 @@
       "version": "0.8.0-beta.0",
       "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.8.0-beta.0.tgz",
       "integrity": "sha512-2ymg6oRBpebeZi9UUNsgQ89bhx01TcTkmNTGnNO88imTmbSgy4nfujrgVEFKWpMTEGA11EDkTt7mqObTPdigIA==",
+      "dev": true,
       "requires": {
         "whatwg-url": "^7.0.0"
       }
@@ -1654,6 +1681,7 @@
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/tr46/-/tr46-1.0.1.tgz",
       "integrity": "sha1-qLE/1r/SSJUZZ0zN5VujaTtwbQk=",
+      "dev": true,
       "requires": {
         "punycode": "^2.1.0"
       }
@@ -1731,12 +1759,14 @@
     "webidl-conversions": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-4.0.2.tgz",
-      "integrity": "sha512-YQ+BmxuTgd6UXZW3+ICGfyqRyHXVlD5GtQr5+qjiNW7bF0cqrzX500HVXPBOvgXb5YnzDd+h0zqyv61KUD7+Sg=="
+      "integrity": "sha512-YQ+BmxuTgd6UXZW3+ICGfyqRyHXVlD5GtQr5+qjiNW7bF0cqrzX500HVXPBOvgXb5YnzDd+h0zqyv61KUD7+Sg==",
+      "dev": true
     },
     "whatwg-url": {
       "version": "7.1.0",
       "resolved": "https://registry.npmjs.org/whatwg-url/-/whatwg-url-7.1.0.tgz",
       "integrity": "sha512-WUu7Rg1DroM7oQvGWfOiAK21n74Gg+T4elXEQYkOhtyLeWiJFoOGLXPKI/9gzIie9CtwVLm8wtw6YJdKyxSjeg==",
+      "dev": true,
       "requires": {
         "lodash.sortby": "^4.7.0",
         "tr46": "^1.0.1",
diff --git a/package.json b/package.json
index 8a6540b21..98894a046 100644
--- a/package.json
+++ b/package.json
@@ -44,10 +44,9 @@
     "main.js"
   ],
   "dependencies": {
-    "@jridgewell/trace-mapping": "^0.3.5",
+    "@jridgewell/source-map": "^0.3.2",
     "acorn": "^8.5.0",
     "commander": "^2.20.0",
-    "source-map": "~0.8.0-beta.0",
     "source-map-support": "~0.5.20"
   },
   "devDependencies": {
@@ -60,7 +59,8 @@
     "pre-commit": "^1.2.2",
     "rimraf": "^3.0.2",
     "rollup": "2.56.3",
-    "semver": "^7.3.4"
+    "semver": "^7.3.4",
+    "source-map": "~0.8.0-beta.0"
   },
   "scripts": {
     "test": "node test/compress.js && mocha test/mocha",
diff --git a/rollup.config.js b/rollup.config.js
index d32d95af8..377d7ce4e 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -5,7 +5,7 @@ export default () => {
             file: "dist/bundle.min.js",
             format: "umd",
             globals: {
-                "source-map": "sourceMap",
+                "@jridgewell/source-map": "sourceMap",
             },
             name: "Terser",
             sourcemap: false,
diff --git a/test/input/issue-505/output.js b/test/input/issue-505/output.js
index 5a1bc018b..14f8febaa 100644
--- a/test/input/issue-505/output.js
+++ b/test/input/issue-505/output.js
@@ -2,4 +2,4 @@ function test(a){
 "aaaaaaaaaaaaaaaa"
 ;a(err,data),a(err,data)
 }
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsidGVzdCIsImNhbGxiYWNrIiwiZXJyIiwiZGF0YSJdLCJtYXBwaW5ncyI6IkFBQUEsU0FBU0EsS0FBS0M7QUFDVjtDQUNBQSxFQUFTQyxJQUFLQyxNQUNkRixFQUFTQyxJQUFLQyJ9
\ No newline at end of file
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJuYW1lcyI6WyJ0ZXN0IiwiY2FsbGJhY2siLCJlcnIiLCJkYXRhIl0sInNvdXJjZXMiOlsiMCJdLCJtYXBwaW5ncyI6IkFBQUEsU0FBU0EsS0FBS0M7QUFDVjtDQUNBQSxFQUFTQyxJQUFLQyxNQUNkRixFQUFTQyxJQUFLQyJ9
\ No newline at end of file
diff --git a/test/input/issue-520/output.js b/test/input/issue-520/output.js
index f6d138047..0aa3c9632 100644
--- a/test/input/issue-520/output.js
+++ b/test/input/issue-520/output.js
@@ -1,2 +1,2 @@
 new function(){console.log(3)};
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUErQyxJQUFyQyxXQUFnQkEsUUFBUUMsSUFBSSIsInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl19
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJuYW1lcyI6WyJjb25zb2xlIiwibG9nIl0sInNvdXJjZXMiOlsic3RkaW4iXSwic291cmNlc0NvbnRlbnQiOlsiY2xhc3MgRm9vIHsgY29uc3RydWN0b3IoKXtjb25zb2xlLmxvZygxKzIpO30gfSBuZXcgRm9vKCk7XG4iXSwibWFwcGluZ3MiOiJBQUErQyxJQUFyQyxXQUFnQkEsUUFBUUMsSUFBSSJ9
diff --git a/test/input/source-maps/expect.js b/test/input/source-maps/expect.js
index b911f3f8d..57cce7b94 100644
--- a/test/input/source-maps/expect.js
+++ b/test/input/source-maps/expect.js
@@ -1,2 +1,2 @@
 function _toConsumableArray(arr){if(Array.isArray(arr)){for(var i=0,arr2=Array(arr.length);i<arr.length;i++){arr2[i]=arr[i]}return arr2}else{return Array.from(arr)}}var _require=require("bar"),foo=_require.foo;var _require2=require("world"),hello=_require2.hello;foo.x.apply(foo,_toConsumableArray(foo.y(hello.z)));
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImlucHV0Mi5qcyJdLCJuYW1lcyI6WyJyZXF1aXJlIiwiYXJyIl0sIm1hcHBpbmdzIjoiMEpBQWNBLEtBQVFDIiwic291cmNlc0NvbnRlbnQiOlsiY29uc3Qge2Zvb30gPSByZXF1aXJlKFwiYmFyXCIpO1xuY29uc3Qge2hlbGxvfSA9IHJlcXVpcmUoXCJ3b3JsZFwiKTtcblxuZm9vLngoLi4uZm9vLnkoaGVsbG8ueikpO1xuIl19
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJuYW1lcyI6WyJyZXF1aXJlIiwiYXJyIl0sInNvdXJjZXMiOlsiaW5wdXQyLmpzIl0sInNvdXJjZXNDb250ZW50IjpbImNvbnN0IHtmb299ID0gcmVxdWlyZShcImJhclwiKTtcbmNvbnN0IHtoZWxsb30gPSByZXF1aXJlKFwid29ybGRcIik7XG5cbmZvby54KC4uLmZvby55KGhlbGxvLnopKTtcbiJdLCJtYXBwaW5ncyI6IjBKQUFjQSxLQUFRQyJ9
diff --git a/test/mocha/cli-2.js b/test/mocha/cli-2.js
index 6e3fa614e..2676963fb 100644
--- a/test/mocha/cli-2.js
+++ b/test/mocha/cli-2.js
@@ -21,7 +21,7 @@ describe("bin/terser (2)", function() {
 
             assert.strictEqual(stdout, [
                 '"use strict";var foo=function foo(x){return"foo "+x};console.log(foo("bar"));',
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImluZGV4LmpzIl0sIm5hbWVzIjpbImZvbyIsIngiLCJjb25zb2xlIiwibG9nIl0sIm1hcHBpbmdzIjoiYUFBQSxJQUFJQSxJQUFNLFNBQU5BLElBQU1DLEdBQUEsTUFBSyxPQUFTQSxHQUN4QkMsUUFBUUMsSUFBSUgsSUFBSSJ9",
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJuYW1lcyI6WyJmb28iLCJ4IiwiY29uc29sZSIsImxvZyJdLCJzb3VyY2VzIjpbImluZGV4LmpzIl0sIm1hcHBpbmdzIjoiYUFBQSxJQUFJQSxJQUFNLFNBQU5BLElBQU1DLEdBQUEsTUFBSyxPQUFTQSxHQUN4QkMsUUFBUUMsSUFBSUgsSUFBSSJ9",
                 ""
             ].join("\n"));
             done();
@@ -46,7 +46,7 @@ describe("bin/terser (2)", function() {
 
             assert.strictEqual(stdout, [
                 'function foo(){return function(){console.log("PASS")}}foo()();',
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInRlc3QvaW5wdXQvaXNzdWUtMjMxMC9pbnB1dC5qcyJdLCJuYW1lcyI6WyJmb28iLCJjb25zb2xlIiwibG9nIiwiZiJdLCJtYXBwaW5ncyI6IkFBQUEsU0FBU0EsTUFDTCxPQUFPLFdBQ0hDLFFBQVFDLElBQUksU0FLUkYsS0FDUkcifQ==",
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJuYW1lcyI6WyJmb28iLCJjb25zb2xlIiwibG9nIiwiZiJdLCJzb3VyY2VzIjpbInRlc3QvaW5wdXQvaXNzdWUtMjMxMC9pbnB1dC5qcyJdLCJtYXBwaW5ncyI6IkFBQUEsU0FBU0EsTUFDTCxPQUFPLFdBQ0hDLFFBQVFDLElBQUksU0FLUkYsS0FDUkcifQ==",
                 ""
             ].join("\n"));
             done();
diff --git a/test/mocha/minify.js b/test/mocha/minify.js
index 189fdb563..4fc4c36b9 100644
--- a/test/mocha/minify.js
+++ b/test/mocha/minify.js
@@ -321,7 +321,7 @@ describe("minify", function() {
             });
             var code = result.code;
             assert.strictEqual(code, "var a=function(n){return n};\n" +
-                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbIjAiXSwibmFtZXMiOlsiYSIsImZvbyJdLCJtYXBwaW5ncyI6IkFBQUEsSUFBSUEsRUFBSSxTQUFTQyxHQUFPLE9BQU9BIn0=");
+                "//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJuYW1lcyI6WyJhIiwiZm9vIl0sInNvdXJjZXMiOlsiMCJdLCJtYXBwaW5ncyI6IkFBQUEsSUFBSUEsRUFBSSxTQUFTQyxHQUFPLE9BQU9BIn0=");
         });
         it("should not append source map to output js when sourceMapInline is not enabled", async function() {
             var result = await minify("var a = function(foo) { return foo; };");
diff --git a/test/mocha/sourcemaps.js b/test/mocha/sourcemaps.js
index cb8f31215..6b38c2507 100644
--- a/test/mocha/sourcemaps.js
+++ b/test/mocha/sourcemaps.js
@@ -1,11 +1,11 @@
 import assert from "assert";
 import { readFileSync } from "fs";
-import source_map_module from "source-map"
+import source_map_module from "source-map";
 import { assertCodeWithInlineMapEquals } from "./utils.js";
 import { to_ascii } from "../../lib/minify.js";
 import { minify } from "../../main.js";
 
-const { SourceMapConsumer } = source_map_module
+const { SourceMapConsumer } = source_map_module;
 
 function read(path) {
     return readFileSync(path, "utf8");
@@ -96,7 +96,12 @@ describe("sourcemaps", function() {
         });
         if (result.error) throw result.error;
         assert.strictEqual(result.code, "({}).wat([]);");
-        assert.strictEqual(result.map, '{"version":3,"sources":["0"],"names":["wat"],"mappings":"CAAU,IACNA,IAAI"}');
+        assert.deepStrictEqual(JSON.parse(result.map), {
+            version: 3,
+            sources: ["0"],
+            names: ["wat"],
+            mappings: "CAAU,IACNA,IAAI",
+        });
     });
     it("Should mark class literals", async function() {
         var result = await minify([
@@ -109,7 +114,12 @@ describe("sourcemaps", function() {
         });
         if (result.error) throw result.error;
         assert.strictEqual(result.code, "(class{}).wat(class{});");
-        assert.strictEqual(result.map, '{"version":3,"sources":["0"],"names":["wat"],"mappings":"CACU,SACNA,IAFJ"}');
+        assert.deepStrictEqual(JSON.parse(result.map), {
+            version: 3,
+            sources: ["0"],
+            names: ["wat"],
+            mappings: "CACU,SACNA,IAFJ",
+        });
     });
     it("Should give correct sourceRoot", async function() {
         var code = "console.log(42);";
@@ -120,7 +130,13 @@ describe("sourcemaps", function() {
         });
         if (result.error) throw result.error;
         assert.strictEqual(result.code, code);
-        assert.strictEqual(result.map, '{"version":3,"sources":["0"],"names":["console","log"],"mappings":"AAAAA,QAAQC,IAAI","sourceRoot":"//foo.bar/"}');
+        assert.deepStrictEqual(JSON.parse(result.map), {
+            version: 3,
+            sources: ["0"],
+            names: ["console","log"],
+            mappings: "AAAAA,QAAQC,IAAI",
+            sourceRoot: "//foo.bar/",
+        });
     });
     it("Should return source map as object when asObject is given", async function() {
         var code = "console.log(42);";
@@ -131,7 +147,12 @@ describe("sourcemaps", function() {
         });
         if (result.error) throw result.error;
         assert.strictEqual(result.code, code);
-        assert.deepStrictEqual(result.map, {"version":3,"sources":["0"],"names":["console","log"],"mappings":"AAAAA,QAAQC,IAAI"});
+        assert.deepStrictEqual(result.map, {
+            version: 3,
+            sources: ["0"],
+            names: ["console","log"],
+            mappings: "AAAAA,QAAQC,IAAI",
+        });
     });
 
     it("Should grab names from methods and properties correctly", async () => {
@@ -191,8 +212,8 @@ describe("sourcemaps", function() {
             if (result.error) throw result.error;
             var map = JSON.parse(result.map);
             assert.equal(map.file, "simple.min.js");
-            assert.equal(map.sourcesContent.length, 1);
-            assert.equal(map.sourcesContent[0], 'let foo = x => "foo " + x;\nconsole.log(foo("bar"));');
+            assert.deepEqual(map.sources, ["index.js"]);
+            assert.deepEqual(map.sourcesContent, ['let foo = x => "foo " + x;\nconsole.log(foo("bar"));']);
         });
         it("Should process inline source map", async function() {
             var result = await minify(read("./test/input/issue-520/input.js"), {
diff --git a/tools/terser.d.ts b/tools/terser.d.ts
index 571b5f0fe..0ec08017b 100644
--- a/tools/terser.d.ts
+++ b/tools/terser.d.ts
@@ -1,6 +1,6 @@
 /// <reference lib="es2015" />
 
-import { RawSourceMap } from 'source-map';
+import { SectionedSourceMapInput, EncodedSourceMap, DecodedSourceMap } from '@jridgewell/source-map';
 
 export type ECMA = 5 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020;
 
@@ -193,12 +193,13 @@ export interface MinifyOptions {
 
 export interface MinifyOutput {
     code?: string;
-    map?: RawSourceMap | string;
+    map?: EncodedSourceMap | string;
+    decoded_map?: DecodedSourceMap | null;
 }
 
 export interface SourceMapOptions {
     /** Source map object, 'inline' or source map file content */
-    content?: RawSourceMap | string;
+    content?: SectionedSourceMapInput | string;
     includeSources?: boolean;
     filename?: string;
     root?: string;