diff --git a/lib/ConcatSource.js b/lib/ConcatSource.js
index 2e9a4d6..f8047cd 100644
--- a/lib/ConcatSource.js
+++ b/lib/ConcatSource.js
@@ -6,7 +6,7 @@
 
 const Source = require("./Source");
 const RawSource = require("./RawSource");
-const { SourceNode, SourceMapConsumer } = require("source-map");
+const { SourceNode, SourceMapConsumer } = require("source-map-sync");
 const { SourceListMap, fromStringWithSourceMap } = require("source-list-map");
 const { getSourceAndMap, getMap } = require("./helpers");
 
@@ -105,10 +105,13 @@ class ConcatSource extends Source {
 				if (typeof item.node === "function") return item.node(options);
 				const sourceAndMap = item.sourceAndMap(options);
 				if (sourceAndMap.map) {
-					return SourceNode.fromStringWithSourceMap(
+					const consumer = new SourceMapConsumer(sourceAndMap.map);
+					const node = SourceNode.fromStringWithSourceMap(
 						sourceAndMap.source,
-						new SourceMapConsumer(sourceAndMap.map)
+						consumer
 					);
+					consumer.destroy();
+					return node;
 				} else {
 					return sourceAndMap.source;
 				}
diff --git a/lib/OriginalSource.js b/lib/OriginalSource.js
index 921a210..260221c 100644
--- a/lib/OriginalSource.js
+++ b/lib/OriginalSource.js
@@ -5,7 +5,7 @@
 "use strict";
 
 const Source = require("./Source");
-const { SourceNode } = require("source-map");
+const { SourceNode } = require("source-map-sync");
 const { SourceListMap } = require("source-list-map");
 const { getSourceAndMap, getMap } = require("./helpers");
 
diff --git a/lib/PrefixSource.js b/lib/PrefixSource.js
index d7872dd..668ae45 100644
--- a/lib/PrefixSource.js
+++ b/lib/PrefixSource.js
@@ -6,7 +6,7 @@
 
 const Source = require("./Source");
 const RawSource = require("./RawSource");
-const { SourceNode } = require("source-map");
+const { SourceNode } = require("source-map-sync");
 const { getSourceAndMap, getMap } = require("./helpers");
 
 const REPLACE_REGEX = /\n(?=.|\s)/g;
diff --git a/lib/RawSource.js b/lib/RawSource.js
index 1c0a47e..a880aad 100644
--- a/lib/RawSource.js
+++ b/lib/RawSource.js
@@ -5,7 +5,7 @@
 "use strict";
 
 const Source = require("./Source");
-const { SourceNode } = require("source-map");
+const { SourceNode } = require("source-map-sync");
 const { SourceListMap } = require("source-list-map");
 
 class RawSource extends Source {
diff --git a/lib/ReplaceSource.js b/lib/ReplaceSource.js
index 5e8b09e..627dbf1 100644
--- a/lib/ReplaceSource.js
+++ b/lib/ReplaceSource.js
@@ -5,7 +5,7 @@
 "use strict";
 
 const Source = require("./Source");
-const { SourceNode } = require("source-map");
+const { SourceNode } = require("source-map-sync");
 const { getSourceAndMap, getMap, getNode, getListMap } = require("./helpers");
 
 class Replacement {
diff --git a/lib/SourceMapSource.js b/lib/SourceMapSource.js
index 8508ff8..1088d55 100644
--- a/lib/SourceMapSource.js
+++ b/lib/SourceMapSource.js
@@ -5,7 +5,7 @@
 "use strict";
 
 const Source = require("./Source");
-const { SourceNode, SourceMapConsumer } = require("source-map");
+const { SourceNode, SourceMapConsumer } = require("source-map-sync");
 const { SourceListMap, fromStringWithSourceMap } = require("source-list-map");
 const { getSourceAndMap, getMap } = require("./helpers");
 const applySourceMap = require("./applySourceMap");
@@ -188,19 +188,23 @@ class SourceMapSource extends Source {
 		this._ensureValueString();
 		this._ensureSourceMapObject();
 		this._ensureOriginalSourceString();
+		const consumer = new SourceMapConsumer(this._sourceMapAsObject);
 		let node = SourceNode.fromStringWithSourceMap(
 			this._valueAsString,
-			new SourceMapConsumer(this._sourceMapAsObject)
+			consumer
 		);
+		consumer.destroy();
 		node.setSourceContent(this._name, this._originalSourceAsString);
 		if (this._hasInnerSourceMap) {
 			this._ensureInnerSourceMapObject();
+			const consumer = new SourceMapConsumer(this._innerSourceMapAsObject);
 			node = applySourceMap(
 				node,
-				new SourceMapConsumer(this._innerSourceMapAsObject),
+				consumer,
 				this._name,
 				this._removeOriginalSource
 			);
+			consumer.destroy();
 		}
 		return node;
 	}
diff --git a/lib/applySourceMap.js b/lib/applySourceMap.js
index ab65bac..8353999 100644
--- a/lib/applySourceMap.js
+++ b/lib/applySourceMap.js
@@ -5,8 +5,8 @@
 
 "use strict";
 
-const SourceNode = require("source-map").SourceNode;
-const SourceMapConsumer = require("source-map").SourceMapConsumer;
+const SourceNode = require("source-map-sync").SourceNode;
+const SourceMapConsumer = require("source-map-sync").SourceMapConsumer;
 
 const applySourceMap = function (
 	sourceNode,
@@ -201,6 +201,7 @@ const applySourceMap = function (
 
 	// Put output into the resulting SourceNode
 	l2rResult.add(l2rOutput);
+	sourceMapConsumer.destroy();
 	return l2rResult;
 };
 
diff --git a/lib/helpers.js b/lib/helpers.js
index b3084e2..3741ff7 100644
--- a/lib/helpers.js
+++ b/lib/helpers.js
@@ -4,7 +4,7 @@
 */
 "use strict";
 
-const { SourceNode, SourceMapConsumer } = require("source-map");
+const { SourceNode, SourceMapConsumer } = require("source-map-sync");
 const { SourceListMap, fromStringWithSourceMap } = require("source-list-map");
 
 exports.getSourceAndMap = (inputSource, options) => {
@@ -55,10 +55,13 @@ exports.getNode = (source, options) => {
 	} else {
 		const sourceAndMap = source.sourceAndMap(options);
 		if (sourceAndMap.map) {
-			return SourceNode.fromStringWithSourceMap(
+			const consumer = new SourceMapConsumer(sourceAndMap.map);
+			const node = SourceNode.fromStringWithSourceMap(
 				sourceAndMap.source,
-				new SourceMapConsumer(sourceAndMap.map)
+				consumer
 			);
+			consumer.destroy();
+			return node;
 		} else {
 			return new SourceNode(null, null, null, sourceAndMap.source);
 		}
diff --git a/package.json b/package.json
index 2cff7f2..ffb2d8b 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
   },
   "dependencies": {
     "source-list-map": "^2.0.1",
-    "source-map": "^0.6.1"
+    "source-map-sync": "0.8.0-beta.2"
   },
   "devDependencies": {
     "coveralls": "^3.0.2",
diff --git a/test/SourceMapSource.js b/test/SourceMapSource.js
index f406d47..1bca3fe 100644
--- a/test/SourceMapSource.js
+++ b/test/SourceMapSource.js
@@ -1,7 +1,7 @@
 const SourceMapSource = require("../").SourceMapSource;
 const OriginalSource = require("../").OriginalSource;
 const ConcatSource = require("../").ConcatSource;
-const SourceNode = require("source-map").SourceNode;
+const SourceNode = require("source-map-sync").SourceNode;
 
 describe("SourceMapSource", () => {
 	it("map correctly", () => {
diff --git a/yarn.lock b/yarn.lock
index 794aa6d..6e30ee3 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3582,6 +3582,13 @@ source-map-support@^0.5.6:
     buffer-from "^1.0.0"
     source-map "^0.6.0"
 
+source-map-sync@0.8.0-beta.2:
+  version "0.8.0-beta.2"
+  resolved "https://registry.yarnpkg.com/source-map-sync/-/source-map-sync-0.8.0-beta.2.tgz#a183568e147738bd249b5a11f402a25c7fa3e9f9"
+  integrity sha512-Q4ejvN6wENaQdYVcq4lMm/vHN9TiSoc/6hQbUhP2DogZ0kYIEYaQlYLbgJ8hEF0eFpQDeEkQAsMiARscl1Ur/Q==
+  dependencies:
+    whatwg-url "^7.0.0"
+
 source-map-url@^0.4.0:
   version "0.4.0"
   resolved "https://registry.yarnpkg.com/source-map-url/-/source-map-url-0.4.0.tgz#3e935d7ddd73631b97659956d55128e87b5084a3"
@@ -3889,6 +3896,13 @@ tough-cookie@^3.0.1:
     psl "^1.1.28"
     punycode "^2.1.1"
 
+tr46@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/tr46/-/tr46-1.0.1.tgz#a8b13fd6bfd2489519674ccde55ba3693b706d09"
+  integrity sha1-qLE/1r/SSJUZZ0zN5VujaTtwbQk=
+  dependencies:
+    punycode "^2.1.0"
+
 tr46@^2.0.2:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/tr46/-/tr46-2.0.2.tgz#03273586def1595ae08fedb38d7733cee91d2479"
@@ -4063,6 +4077,11 @@ walker@^1.0.7, walker@~1.0.5:
   dependencies:
     makeerror "1.0.x"
 
+webidl-conversions@^4.0.2:
+  version "4.0.2"
+  resolved "https://registry.yarnpkg.com/webidl-conversions/-/webidl-conversions-4.0.2.tgz#a855980b1f0b6b359ba1d5d9fb39ae941faa63ad"
+  integrity sha512-YQ+BmxuTgd6UXZW3+ICGfyqRyHXVlD5GtQr5+qjiNW7bF0cqrzX500HVXPBOvgXb5YnzDd+h0zqyv61KUD7+Sg==
+
 webidl-conversions@^5.0.0:
   version "5.0.0"
   resolved "https://registry.yarnpkg.com/webidl-conversions/-/webidl-conversions-5.0.0.tgz#ae59c8a00b121543a2acc65c0434f57b0fc11aff"
@@ -4085,6 +4104,15 @@ whatwg-mimetype@^2.3.0:
   resolved "https://registry.yarnpkg.com/whatwg-mimetype/-/whatwg-mimetype-2.3.0.tgz#3d4b1e0312d2079879f826aff18dbeeca5960fbf"
   integrity sha512-M4yMwr6mAnQz76TbJm914+gPpB/nCwvZbJU28cUD6dR004SAxDLOOSUaB1JDRqLtaOV/vi0IC5lEAGFgrjGv/g==
 
+whatwg-url@^7.0.0:
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/whatwg-url/-/whatwg-url-7.1.0.tgz#c2c492f1eca612988efd3d2266be1b9fc6170d06"
+  integrity sha512-WUu7Rg1DroM7oQvGWfOiAK21n74Gg+T4elXEQYkOhtyLeWiJFoOGLXPKI/9gzIie9CtwVLm8wtw6YJdKyxSjeg==
+  dependencies:
+    lodash.sortby "^4.7.0"
+    tr46 "^1.0.1"
+    webidl-conversions "^4.0.2"
+
 whatwg-url@^8.0.0:
   version "8.1.0"
   resolved "https://registry.yarnpkg.com/whatwg-url/-/whatwg-url-8.1.0.tgz#c628acdcf45b82274ce7281ee31dd3c839791771"