diff --git a/.changeset/tame-cars-press.md b/.changeset/tame-cars-press.md
new file mode 100644
index 0000000000..d95edad332
--- /dev/null
+++ b/.changeset/tame-cars-press.md
@@ -0,0 +1,6 @@
+---
+'@backstage/plugin-scaffolder': patch
+'@backstage/plugin-techdocs': patch
+---
+
+Applied the fix from version 1.0.1 of this package, which is part of the v1.0.2 release of Backstage.
diff --git a/plugins/scaffolder/CHANGELOG.md b/plugins/scaffolder/CHANGELOG.md
index 3b23e83057..aea8b84acd 100644
--- a/plugins/scaffolder/CHANGELOG.md
+++ b/plugins/scaffolder/CHANGELOG.md
@@ -1,5 +1,11 @@
 # @backstage/plugin-scaffolder
 
+## 1.0.1
+
+### Patch Changes
+
+- Pin the `event-source-polyfill` dependency to version 1.0.25
+
 ## 1.0.1-next.1
 
 ### Patch Changes
diff --git a/plugins/scaffolder/package.json b/plugins/scaffolder/package.json
index 76fe863c06..25d4fc1246 100644
--- a/plugins/scaffolder/package.json
+++ b/plugins/scaffolder/package.json
@@ -92,7 +92,7 @@
     "@types/jest": "^26.0.7",
     "@types/node": "^14.14.32",
     "cross-fetch": "^3.1.5",
-    "event-source-polyfill": "^1.0.25",
+    "event-source-polyfill": "1.0.25",
     "msw": "^0.35.0"
   },
   "files": [
diff --git a/plugins/techdocs/CHANGELOG.md b/plugins/techdocs/CHANGELOG.md
index 2e5de77322..f0d9becef4 100644
--- a/plugins/techdocs/CHANGELOG.md
+++ b/plugins/techdocs/CHANGELOG.md
@@ -1,5 +1,11 @@
 # @backstage/plugin-techdocs
 
+## 1.0.1
+
+### Patch Changes
+
+- Pin the `event-source-polyfill` dependency to version 1.0.25
+
 ## 1.0.1-next.1
 
 ### Patch Changes
diff --git a/plugins/techdocs/package.json b/plugins/techdocs/package.json
index f3e9a0c805..24a6538c88 100644
--- a/plugins/techdocs/package.json
+++ b/plugins/techdocs/package.json
@@ -50,7 +50,7 @@
     "@material-ui/lab": "4.0.0-alpha.57",
     "@material-ui/styles": "^4.10.0",
     "dompurify": "^2.2.9",
-    "event-source-polyfill": "^1.0.25",
+    "event-source-polyfill": "1.0.25",
     "git-url-parse": "^11.6.0",
     "lodash": "^4.17.21",
     "react-router": "6.0.0-beta.0",
diff --git a/yarn.lock b/yarn.lock
index 64a02725dd..8431b3bd67 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -12093,7 +12093,7 @@ etag@~1.8.1:
   resolved "https://registry.npmjs.org/etag/-/etag-1.8.1.tgz#41ae2eeb65efa62268aebfea83ac7d79299b0887"
   integrity sha1-Qa4u62XvpiJorr/qg6x9eSmbCIc=
 
-event-source-polyfill@^1.0.25:
+event-source-polyfill@1.0.25:
   version "1.0.25"
   resolved "https://registry.npmjs.org/event-source-polyfill/-/event-source-polyfill-1.0.25.tgz#d8bb7f99cb6f8119c2baf086d9f6ee0514b6d9c8"
   integrity sha512-hQxu6sN1Eq4JjoI7ITdQeGGUN193A2ra83qC0Ltm9I2UJVAten3OFVN6k5RX4YWeCS0BoC8xg/5czOCIHVosQg==