diff --git a/lib/precompiler.js b/lib/precompiler.js
index 2b3fb69d..1fb0093d 100644
--- a/lib/precompiler.js
+++ b/lib/precompiler.js
@@ -153,7 +153,8 @@ function loadFiles(opts, callback) {
   );
 }
 
-module.exports.cli = function (opts) {
+module.exports.cli = async function (opts) {
+  // TODO what implications does this have?
   if (opts.version) {
     console.log(Handlebars.VERSION);
     return;
@@ -222,7 +223,7 @@ module.exports.cli = function (opts) {
     output.add('{};\n');
   }
 
-  opts.templates.forEach(function (template) {
+  for (const template of opts.templates) {
     let options = {
       knownHelpers: known,
       knownHelpersOnly: opts.o,
@@ -239,11 +240,12 @@ module.exports.cli = function (opts) {
 
     // If we are generating a source map, we have to reconstruct the SourceNode object
     if (opts.map) {
-      let consumer = new SourceMapConsumer(precompiled.map);
+      let consumer = await new SourceMapConsumer(precompiled.map);
       precompiled = SourceNode.fromStringWithSourceMap(
         precompiled.code,
         consumer
       );
+      consumer.destroy();
     }
 
     if (opts.simple) {
@@ -265,7 +267,7 @@ module.exports.cli = function (opts) {
         ');\n',
       ]);
     }
-  });
+  }
 
   // Output the content
   if (!opts.simple) {
diff --git a/package-lock.json b/package-lock.json
index 35076066..22120e49 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,7 +11,7 @@
       "dependencies": {
         "@handlebars/parser": "^2.1.0",
         "neo-async": "^2.6.2",
-        "source-map": "^0.6.1",
+        "source-map": "^0.7.4",
         "yargs": "^16.2.0"
       },
       "bin": {
@@ -8230,6 +8230,15 @@
         "ms": "^2.1.1"
       }
     },
+    "node_modules/istanbul-lib-source-maps/node_modules/source-map": {
+      "version": "0.6.1",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+      "dev": true,
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/istanbul-reports": {
       "version": "2.2.7",
       "resolved": "https://registry.npmjs.org/istanbul-reports/-/istanbul-reports-2.2.7.tgz",
@@ -9559,6 +9568,15 @@
         "source-map": "^0.6.1"
       }
     },
+    "node_modules/merge-source-map/node_modules/source-map": {
+      "version": "0.6.1",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+      "dev": true,
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/merge-stream": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/merge-stream/-/merge-stream-2.0.0.tgz",
@@ -12897,11 +12915,11 @@
       "dev": true
     },
     "node_modules/source-map": {
-      "version": "0.6.1",
-      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
-      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+      "version": "0.7.4",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.7.4.tgz",
+      "integrity": "sha512-l3BikUxvPOcn5E74dZiq5BGsTb5yEwhaTSzccU6t4sDOH8NWJCstKO5QT2CvtFoK6F0saL7p9xHAqHOlCPJygA==",
       "engines": {
-        "node": ">=0.10.0"
+        "node": ">= 8"
       }
     },
     "node_modules/source-map-resolve": {
@@ -13798,6 +13816,15 @@
         "node": ">=0.8.0"
       }
     },
+    "node_modules/uglify-js/node_modules/source-map": {
+      "version": "0.6.1",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+      "dev": true,
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/uglify-to-browserify": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/uglify-to-browserify/-/uglify-to-browserify-1.0.2.tgz",
@@ -21169,6 +21196,12 @@
           "requires": {
             "ms": "^2.1.1"
           }
+        },
+        "source-map": {
+          "version": "0.6.1",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+          "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+          "dev": true
         }
       }
     },
@@ -22223,6 +22256,14 @@
       "dev": true,
       "requires": {
         "source-map": "^0.6.1"
+      },
+      "dependencies": {
+        "source-map": {
+          "version": "0.6.1",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+          "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+          "dev": true
+        }
       }
     },
     "merge-stream": {
@@ -24943,9 +24984,9 @@
       "dev": true
     },
     "source-map": {
-      "version": "0.6.1",
-      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
-      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g=="
+      "version": "0.7.4",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.7.4.tgz",
+      "integrity": "sha512-l3BikUxvPOcn5E74dZiq5BGsTb5yEwhaTSzccU6t4sDOH8NWJCstKO5QT2CvtFoK6F0saL7p9xHAqHOlCPJygA=="
     },
     "source-map-resolve": {
       "version": "0.5.3",
@@ -25663,6 +25704,14 @@
       "requires": {
         "commander": "~2.20.3",
         "source-map": "~0.6.1"
+      },
+      "dependencies": {
+        "source-map": {
+          "version": "0.6.1",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+          "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+          "dev": true
+        }
       }
     },
     "uglify-to-browserify": {
diff --git a/package.json b/package.json
index 8d732c21..9e921f81 100644
--- a/package.json
+++ b/package.json
@@ -22,7 +22,7 @@
   "dependencies": {
     "@handlebars/parser": "^2.1.0",
     "neo-async": "^2.6.2",
-    "source-map": "^0.6.1",
+    "source-map": "^0.7.4",
     "yargs": "^16.2.0"
   },
   "peerDependencies": {
diff --git a/spec/precompiler.js b/spec/precompiler.js
index 857f64e2..976f51d6 100644
--- a/spec/precompiler.js
+++ b/spec/precompiler.js
@@ -83,14 +83,15 @@ describe('precompiler', function () {
     console.error = errorLogFunction;
   });
 
-  it('should output version', function () {
-    Precompiler.cli({ templates: [], version: true });
+  it('should output version', async function () {
+    // TODO do this for all other tests
+    await Precompiler.cli({ templates: [], version: true });
     equals(log, Handlebars.VERSION);
   });
   it('should throw if lacking templates', function () {
     shouldThrow(
-      function () {
-        Precompiler.cli({ templates: [] });
+      async function () {
+        await Precompiler.cli({ templates: [] });
       },
       Handlebars.Exception,
       'Must define at least one template or directory.'
diff --git a/spec/source-map.js b/spec/source-map.js
index 5eb10967..81274245 100644
--- a/spec/source-map.js
+++ b/spec/source-map.js
@@ -21,7 +21,7 @@ describe('source-map', function () {
     equal(!!template.code, true);
     equal(!!template.map, !CompilerContext.browser);
   });
-  it('should map source properly', function () {
+  it('should map source properly', async function () {
     var templateSource =
         '  b{{hello}}  \n  {{bar}}a {{#block arg hash=(subex 1 subval)}}{{/block}}',
       template = Handlebars.precompile(templateSource, {
@@ -30,13 +30,15 @@ describe('source-map', function () {
       });
 
     if (template.map) {
-      var consumer = new SourceMapConsumer(template.map),
+      var consumer = await new SourceMapConsumer(template.map),
         lines = template.code.split('\n'),
         srcLines = templateSource.split('\n'),
         generated = grepLine('"  b"', lines),
         source = grepLine('  b', srcLines);
 
       var mapped = consumer.originalPositionFor(generated);
+      consumer.destroy();
+
       equal(mapped.line, source.line);
       equal(mapped.column, source.column);
     }
diff --git a/tests/print-script.js b/tests/print-script.js
index c8d9ddbb..e92b0e2a 100755
--- a/tests/print-script.js
+++ b/tests/print-script.js
@@ -1,114 +1,119 @@
 /* eslint-disable no-console, no-var */
 // Util script for debugging source code generation issues
+// Example: `node tests/print-script.js "Test: {{ foo }}" -v`
 
-var script = process.argv[2].replace(/\\n/g, '\n'),
-  verbose = process.argv[3] === '-v';
+const Handlebars = require('./../lib');
+const SourceMap = require('source-map');
+const SourceMapConsumer = SourceMap.SourceMapConsumer;
 
-var Handlebars = require('./../lib'),
-  SourceMap = require('source-map'),
-  SourceMapConsumer = SourceMap.SourceMapConsumer;
+const script = process.argv[2].replace(/\\n/g, '\n');
+const verbose = process.argv[3] === '-v';
 
-var template = Handlebars.precompile(script, {
-  srcName: 'input.hbs',
-  destName: 'output.js',
+async function generateSourceCode(script, verbose) {
+  var template = Handlebars.precompile(script, {
+    srcName: 'input.hbs',
+    destName: 'output.js',
 
-  assumeObjects: true,
-  compat: false,
-  strict: true,
-  trackIds: true,
-  knownHelpersOnly: false,
-});
+    assumeObjects: true,
+    compat: false,
+    strict: true,
+    knownHelpersOnly: false,
+  });
 
-if (!verbose) {
-  console.log(template);
-} else {
-  var consumer = new SourceMapConsumer(template.map),
-    lines = template.code.split('\n'),
-    srcLines = script.split('\n');
+  if (!verbose) {
+    console.log(template);
+  } else {
+    const consumer = await new SourceMapConsumer(template.map);
+    let lines = template.code.split('\n');
+    let srcLines = script.split('\n');
 
-  console.log();
-  console.log('Source:');
-  srcLines.forEach(function (source, index) {
-    console.log(index + 1, source);
-  });
-  console.log();
-  console.log('Generated:');
-  console.log(template.code);
-  lines.forEach(function (source, index) {
-    console.log(index + 1, source);
-  });
-  console.log();
-  console.log('Map:');
-  console.log(template.map);
-  console.log();
+    console.log();
+    console.log('Source:');
+    srcLines.forEach(function (source, index) {
+      console.log(index + 1, source);
+    });
+    console.log();
+    console.log('Generated:');
+    console.log(template.code);
+    lines.forEach(function (source, index) {
+      console.log(index + 1, source);
+    });
+    console.log();
+    console.log('Map:');
+    console.log(template.map);
+    console.log();
 
-  // eslint-disable-next-line no-inner-declarations
-  function collectSource(lines, lineName, colName, order) {
-    var ret = {},
-      ordered = [],
-      last;
+    // eslint-disable-next-line no-inner-declarations
+    function collectSource(lines, lineName, colName, order) {
+      var ret = {},
+        ordered = [],
+        last;
 
-    function collect(current) {
-      if (last) {
-        var mapLines = lines.slice(
-          last[lineName] - 1,
-          current && current[lineName]
-        );
-        if (mapLines.length) {
-          if (current) {
-            mapLines[mapLines.length - 1] = mapLines[mapLines.length - 1].slice(
-              0,
-              current[colName]
-            );
+      function collect(current) {
+        if (last) {
+          var mapLines = lines.slice(
+            last[lineName] - 1,
+            current && current[lineName]
+          );
+          if (mapLines.length) {
+            if (current) {
+              mapLines[mapLines.length - 1] = mapLines[
+                mapLines.length - 1
+              ].slice(0, current[colName]);
+            }
+            mapLines[0] = mapLines[0].slice(last[colName]);
           }
-          mapLines[0] = mapLines[0].slice(last[colName]);
+          ret[last[lineName] + ':' + last[colName]] = mapLines.join('\n');
+          ordered.push({
+            startLine: last[lineName],
+            startCol: last[colName],
+            endLine: current && current[lineName],
+          });
         }
-        ret[last[lineName] + ':' + last[colName]] = mapLines.join('\n');
-        ordered.push({
-          startLine: last[lineName],
-          startCol: last[colName],
-          endLine: current && current[lineName],
-        });
+        last = current;
       }
-      last = current;
-    }
 
-    consumer.eachMapping(collect, undefined, order);
-    collect();
+      consumer.eachMapping(collect, undefined, order);
+      collect();
 
-    return ret;
-  }
+      return ret;
+    }
 
-  srcLines = collectSource(
-    srcLines,
-    'originalLine',
-    'originalColumn',
-    SourceMapConsumer.ORIGINAL_ORDER
-  );
-  lines = collectSource(lines, 'generatedLine', 'generatedColumn');
+    srcLines = collectSource(
+      srcLines,
+      'originalLine',
+      'originalColumn',
+      SourceMapConsumer.ORIGINAL_ORDER
+    );
+    lines = collectSource(lines, 'generatedLine', 'generatedColumn');
 
-  consumer.eachMapping(function (mapping) {
-    var originalSrc =
-        srcLines[mapping.originalLine + ':' + mapping.originalColumn],
-      generatedSrc =
-        lines[mapping.generatedLine + ':' + mapping.generatedColumn];
+    consumer.eachMapping(function (mapping) {
+      var originalSrc =
+          srcLines[mapping.originalLine + ':' + mapping.originalColumn],
+        generatedSrc =
+          lines[mapping.generatedLine + ':' + mapping.generatedColumn];
 
-    if (!mapping.originalLine) {
-      console.log(
-        'generated',
-        mapping.generatedLine + ':' + mapping.generatedColumn,
-        generatedSrc
-      );
-    } else {
-      console.log(
-        'map',
-        mapping.source,
-        mapping.originalLine + ':' + mapping.originalColumn,
-        originalSrc,
-        '->',
-        mapping.generatedLine + ':' + mapping.generatedColumn,
-        generatedSrc
-      );
-    }
-  });
+      if (!mapping.originalLine) {
+        console.log(
+          'generated',
+          mapping.generatedLine + ':' + mapping.generatedColumn,
+          generatedSrc
+        );
+      } else {
+        console.log(
+          'map',
+          mapping.source,
+          mapping.originalLine + ':' + mapping.originalColumn,
+          originalSrc,
+          '->',
+          mapping.generatedLine + ':' + mapping.generatedColumn,
+          generatedSrc
+        );
+      }
+    });
+
+    consumer.destroy();
+  }
 }
+
+generateSourceCode(script, verbose);