diff --git a/packages/jest-reporters/package.json b/packages/jest-reporters/package.json
index a56037794bf7..02c2d0eff3ce 100644
--- a/packages/jest-reporters/package.json
+++ b/packages/jest-reporters/package.json
@@ -16,7 +16,7 @@
     "glob": "^7.1.2",
     "graceful-fs": "^4.2.4",
     "istanbul-lib-coverage": "^3.0.0",
-    "istanbul-lib-instrument": "^4.0.0",
+    "istanbul-lib-instrument": "^4.0.3",
     "istanbul-lib-report": "^3.0.0",
     "istanbul-lib-source-maps": "^4.0.0",
     "istanbul-reports": "^3.0.2",
diff --git a/packages/jest-transform/src/__tests__/__snapshots__/script_transformer.test.js.snap b/packages/jest-transform/src/__tests__/__snapshots__/script_transformer.test.js.snap
index f2e35813f3b9..8cc51acac4fa 100644
--- a/packages/jest-transform/src/__tests__/__snapshots__/script_transformer.test.js.snap
+++ b/packages/jest-transform/src/__tests__/__snapshots__/script_transformer.test.js.snap
@@ -112,18 +112,19 @@ function cov_25u22311x4() {
   }
 
   var actualCoverage = coverage[path];
-
-  cov_25u22311x4 = function () {
-    return actualCoverage;
-  };
-
+  {
+    // @ts-ignore
+    cov_25u22311x4 = function () {
+      return actualCoverage;
+    };
+  }
   return actualCoverage;
 }
 
 cov_25u22311x4();
 cov_25u22311x4().s[0]++;
 module.exports = "banana";
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImJhbmFuYS5qcyJdLCJuYW1lcyI6WyJtb2R1bGUiLCJleHBvcnRzIl0sIm1hcHBpbmdzIjoiOzs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7QUFBQUEsTUFBTSxDQUFDQyxPQUFQLEdBQWlCLFFBQWpCIiwic291cmNlc0NvbnRlbnQiOlsibW9kdWxlLmV4cG9ydHMgPSBcImJhbmFuYVwiOyJdfQ==
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImJhbmFuYS5qcyJdLCJuYW1lcyI6WyJtb2R1bGUiLCJleHBvcnRzIl0sIm1hcHBpbmdzIjoiOzs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7QUFlWTs7Ozs7Ozs7OztBQWZaQSxNQUFNLENBQUNDLE9BQVAsR0FBaUIsUUFBakIiLCJzb3VyY2VzQ29udGVudCI6WyJtb2R1bGUuZXhwb3J0cyA9IFwiYmFuYW5hXCI7Il19
 `;
 
 exports[`ScriptTransformer transforms a file properly 2`] = `
@@ -203,11 +204,12 @@ function cov_23yvu8etmu() {
   }
 
   var actualCoverage = coverage[path];
-
-  cov_23yvu8etmu = function () {
-    return actualCoverage;
-  };
-
+  {
+    // @ts-ignore
+    cov_23yvu8etmu = function () {
+      return actualCoverage;
+    };
+  }
   return actualCoverage;
 }
 
@@ -220,7 +222,7 @@ module.exports = () => {
   cov_23yvu8etmu().s[1]++;
   return "kiwi";
 };
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImtpd2kuanMiXSwibmFtZXMiOlsibW9kdWxlIiwiZXhwb3J0cyJdLCJtYXBwaW5ncyI6Ijs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7O0FBQUFBLE1BQU0sQ0FBQ0MsT0FBUCxHQUFpQixNQUFNO0FBQUE7QUFBQTtBQUFBO0FBQUE7QUFBTSxDQUE3QiIsInNvdXJjZXNDb250ZW50IjpbIm1vZHVsZS5leHBvcnRzID0gKCkgPT4gXCJraXdpXCI7Il19
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbImtpd2kuanMiXSwibmFtZXMiOlsibW9kdWxlIiwiZXhwb3J0cyJdLCJtYXBwaW5ncyI6Ijs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7Ozs7QUFlWTs7Ozs7Ozs7Ozs7QUFmWkEsTUFBTSxDQUFDQyxPQUFQLEdBQWlCLE1BQU07QUFBQTtBQUFBO0FBQUE7QUFBQTtBQUFNLENBQTdCIiwic291cmNlc0NvbnRlbnQiOlsibW9kdWxlLmV4cG9ydHMgPSAoKSA9PiBcImtpd2lcIjsiXX0=
 `;
 
 exports[`ScriptTransformer uses multiple preprocessors 1`] = `
diff --git a/packages/jest-transform/src/__tests__/script_transformer.test.js b/packages/jest-transform/src/__tests__/script_transformer.test.js
index d8d2281e5d78..fd8c31d2b007 100644
--- a/packages/jest-transform/src/__tests__/script_transformer.test.js
+++ b/packages/jest-transform/src/__tests__/script_transformer.test.js
@@ -558,7 +558,8 @@ describe('ScriptTransformer', () => {
       version: 3,
       sources: ['banana.js'],
       names: ['content'],
-      mappings: ';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAAA,OAAO',
+      mappings:
+        ';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAeY;;;;;;;;;;AAfZA,OAAO',
       sourcesContent: ['content'],
     };
     /* eslint-enable */
@@ -596,7 +597,7 @@ describe('ScriptTransformer', () => {
       sources: ['banana.js'],
       names: ['module', 'exports'],
       mappings:
-        ';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAAA,MAAM,CAACC,OAAP,GAAiB,QAAjB',
+        ';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAeY;;;;;;;;;;AAfZA,MAAM,CAACC,OAAP,GAAiB,QAAjB',
       sourcesContent: ['module.exports = "banana";'],
     };
     /* eslint-enable */
diff --git a/yarn.lock b/yarn.lock
index c40a326f6a5f..624b75f1a1eb 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -306,7 +306,7 @@
     chalk "^2.0.0"
     js-tokens "^4.0.0"
 
-"@babel/parser@^7.0.0", "@babel/parser@^7.1.0", "@babel/parser@^7.7.0", "@babel/parser@^7.7.5", "@babel/parser@^7.8.6", "@babel/parser@^7.9.6":
+"@babel/parser@^7.0.0", "@babel/parser@^7.1.0", "@babel/parser@^7.7.0", "@babel/parser@^7.8.6", "@babel/parser@^7.9.6":
   version "7.9.6"
   resolved "https://registry.yarnpkg.com/@babel/parser/-/parser-7.9.6.tgz#3b1bbb30dabe600cd72db58720998376ff653bc7"
   integrity sha512-AoeIEJn8vt+d/6+PXDRPaksYhnlbMIiejioBZvvMQsOjW/JYK6k/0dKnvvP3EhK5GfMBWDPtrxRtegWdAcdq9Q==
@@ -994,7 +994,7 @@
   dependencies:
     regenerator-runtime "^0.13.4"
 
-"@babel/template@^7.0.0", "@babel/template@^7.3.3", "@babel/template@^7.7.4", "@babel/template@^7.8.3", "@babel/template@^7.8.6":
+"@babel/template@^7.0.0", "@babel/template@^7.3.3", "@babel/template@^7.8.3", "@babel/template@^7.8.6":
   version "7.8.6"
   resolved "https://registry.yarnpkg.com/@babel/template/-/template-7.8.6.tgz#86b22af15f828dfb086474f964dcc3e39c43ce2b"
   integrity sha512-zbMsPMy/v0PWFZEhQJ66bqjhH+z0JgMoBWuikXybgG3Gkd/3t5oQ1Rw2WQhnSrsOmsKXnZOx15tkC4qON/+JPg==
@@ -8003,15 +8003,12 @@ istanbul-lib-coverage@^3.0.0:
   resolved "https://registry.yarnpkg.com/istanbul-lib-coverage/-/istanbul-lib-coverage-3.0.0.tgz#f5944a37c70b550b02a78a5c3b2055b280cec8ec"
   integrity sha512-UiUIqxMgRDET6eR+o5HbfRYP1l0hqkWOs7vNxC/mggutCMUIhWMm8gAHb8tHlyfD3/l6rlgNA5cKdDzEAf6hEg==
 
-istanbul-lib-instrument@^4.0.0:
-  version "4.0.1"
-  resolved "https://registry.yarnpkg.com/istanbul-lib-instrument/-/istanbul-lib-instrument-4.0.1.tgz#61f13ac2c96cfefb076fe7131156cc05907874e6"
-  integrity sha512-imIchxnodll7pvQBYOqUu88EufLCU56LMeFPZZM/fJZ1irYcYdqroaV+ACK1Ila8ls09iEYArp+nqyC6lW1Vfg==
+istanbul-lib-instrument@^4.0.0, istanbul-lib-instrument@^4.0.3:
+  version "4.0.3"
+  resolved "https://registry.yarnpkg.com/istanbul-lib-instrument/-/istanbul-lib-instrument-4.0.3.tgz#873c6fff897450118222774696a3f28902d77c1d"
+  integrity sha512-BXgQl9kf4WTCPCCpmFGoJkz/+uhvm7h7PFKUYxh7qarQd3ER33vHG//qaE8eN25l07YqZPpHXU9I09l/RD5aGQ==
   dependencies:
     "@babel/core" "^7.7.5"
-    "@babel/parser" "^7.7.5"
-    "@babel/template" "^7.7.4"
-    "@babel/traverse" "^7.7.4"
     "@istanbuljs/schema" "^0.1.2"
     istanbul-lib-coverage "^3.0.0"
     semver "^6.3.0"