diff --git a/CHANGELOG.unreleased.md b/CHANGELOG.unreleased.md
index 6c7a41e7..2e52cba9 100644
--- a/CHANGELOG.unreleased.md
+++ b/CHANGELOG.unreleased.md
@@ -146,8 +146,31 @@ Previously, Prettier would sometimes ignore whitespace when formatting comments.
 </div>
 ```
 
+### Handlebars: Improve comment formatting ([#6234] by [@gavinjoyce])
+
+Previously, Prettier would incorrectly decode HTML entiites.
+
+<!-- prettier-ignore -->
+```hbs
+// Input
+<p>
+  Some escaped characters: &lt; &gt; &amp;
+</p>
+
+// Output (Prettier stable)
+<p>
+  Some escaped characters: < > &
+</p>
+
+// Output (Prettier master)
+<p>
+  Some escaped characters: &lt; &gt; &amp;
+</p>
+```
+
 [#6209]: https://github.com/prettier/prettier/pull/6209
 [#6186]: https://github.com/prettier/prettier/pull/6186
 [#6186]: https://github.com/prettier/prettier/pull/6206
+[#6234]: https://github.com/prettier/prettier/pull/6234
 [@duailibe]: https://github.com/duailibe
 [@gavinjoyce]: https://github.com/gavinjoyce
diff --git a/package.json b/package.json
index dcc40033..09c807eb 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
     "@angular/compiler": "7.2.9",
     "@babel/code-frame": "7.0.0",
     "@babel/parser": "7.2.0",
-    "@glimmer/syntax": "0.39.3",
+    "@glimmer/syntax": "0.41.0",
     "@iarna/toml": "2.2.3",
     "@typescript-eslint/typescript-estree": "1.10.2",
     "angular-estree-parser": "1.1.5",
diff --git a/src/language-handlebars/parser-glimmer.js b/src/language-handlebars/parser-glimmer.js
index a9b13b3b..3c4568b2 100644
--- a/src/language-handlebars/parser-glimmer.js
+++ b/src/language-handlebars/parser-glimmer.js
@@ -8,7 +8,8 @@ function parse(text) {
     return glimmer(text, {
       plugins: {
         ast: []
-      }
+      },
+      mode: "codemod"
     });
     /* istanbul ignore next */
   } catch (error) {
diff --git a/tests/glimmer/__snapshots__/jsfmt.spec.js.snap b/tests/glimmer/__snapshots__/jsfmt.spec.js.snap
index 0d8fe9aa..80f37894 100644
--- a/tests/glimmer/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/glimmer/__snapshots__/jsfmt.spec.js.snap
@@ -1290,6 +1290,35 @@ singleQuote: true
 ================================================================================
 `;
 
+exports[`html-entities.hbs 1`] = `
+====================================options=====================================
+parsers: ["glimmer"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+<p>Some escaped characters: &lt; &gt; &amp;</p>
+=====================================output=====================================
+<p>
+  Some escaped characters: &lt; &gt; &amp;
+</p>
+================================================================================
+`;
+
+exports[`html-entities.hbs 2`] = `
+====================================options=====================================
+parsers: ["glimmer"]
+printWidth: 80
+singleQuote: true
+                                                                                | printWidth
+=====================================input======================================
+<p>Some escaped characters: &lt; &gt; &amp;</p>
+=====================================output=====================================
+<p>
+  Some escaped characters: &lt; &gt; &amp;
+</p>
+================================================================================
+`;
+
 exports[`literals.hbs 1`] = `
 ====================================options=====================================
 parsers: ["glimmer"]
diff --git a/tests/glimmer/html-entities.hbs b/tests/glimmer/html-entities.hbs
new file mode 100644
index 00000000..0c767e88
--- /dev/null
+++ b/tests/glimmer/html-entities.hbs
@@ -0,0 +1 @@
+<p>Some escaped characters: &lt; &gt; &amp;</p>
\ No newline at end of file
diff --git a/yarn.lock b/yarn.lock
index da38e3a3..13bdf066 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -718,25 +718,25 @@
     lodash "^4.17.11"
     to-fast-properties "^2.0.0"
 
-"@glimmer/interfaces@^0.39.3":
-  version "0.39.3"
-  resolved "https://registry.yarnpkg.com/@glimmer/interfaces/-/interfaces-0.39.3.tgz#1d46e1056c9ff3ce6174b82320893c027772e5f4"
-  integrity sha512-tmuZAUau8UbyGh4gLkpC6Vjdm0JP2dibAMMaU/yZG+SGSsQeT+bo+0XcEezscQDPihfXsBX4Z6yq98o15beYEA==
+"@glimmer/interfaces@^0.41.0":
+  version "0.41.0"
+  resolved "https://registry.yarnpkg.com/@glimmer/interfaces/-/interfaces-0.41.0.tgz#3f571a181025406f29faed9006d0a914afb577b1"
+  integrity sha512-d0Ryj8iV3FiyMyT4QpwHNg2QFFEmdzI5cJFcbmC+OmuTe6eOQ52mLDlw1+D+a3ZDv8Jfj3l0QkEcEugCxDY+1Q==
 
-"@glimmer/syntax@0.39.3":
-  version "0.39.3"
-  resolved "https://registry.yarnpkg.com/@glimmer/syntax/-/syntax-0.39.3.tgz#a5220151b00c69fbd728e120dffc7f90fa5b4f24"
-  integrity sha512-Mb/d1hyWKZYANRPKoEGQ4wTc0kkcsjtxyN+J4ps2F1LQ5UKqJxDlgA/Tf9zXNHsd+A8dn25t5NIjQl7KIdsqOg==
+"@glimmer/syntax@0.41.0":
+  version "0.41.0"
+  resolved "https://registry.yarnpkg.com/@glimmer/syntax/-/syntax-0.41.0.tgz#af033e48475e29a4784900c13695925d752f462d"
+  integrity sha512-sYmgUMdK0jX+3ZNX9C2TKvL1YZGsKIcXRicwnzoTC7F56z29CbSCc7o6Zf0CI4L2Q7FSnHDxldlSe48wBAr6vQ==
   dependencies:
-    "@glimmer/interfaces" "^0.39.3"
-    "@glimmer/util" "^0.39.3"
+    "@glimmer/interfaces" "^0.41.0"
+    "@glimmer/util" "^0.41.0"
     handlebars "^4.0.13"
     simple-html-tokenizer "^0.5.7"
 
-"@glimmer/util@^0.39.3":
-  version "0.39.3"
-  resolved "https://registry.yarnpkg.com/@glimmer/util/-/util-0.39.3.tgz#f6b0417c4b0a30f4ea693990f466e3d1eb442d37"
-  integrity sha512-2tzpxdgaQxMu9bHFqTpGDBYDtSWJWQZkBCFfkzCmPrJuCis3YK7m9hzYIaow7CsVLnO44Xmur+Bpq6IM9gVFXw==
+"@glimmer/util@^0.41.0":
+  version "0.41.0"
+  resolved "https://registry.yarnpkg.com/@glimmer/util/-/util-0.41.0.tgz#743fa455d1d7fa0ce29688e932c231a99c0752cf"
+  integrity sha512-aKmQy62eRFhOZET9XmTB8MOA32G1FmD4d9HWL21OfdcGM4IbguRrWLMQc2DRh1YOE2AaT0PBrFrPmpNwFp5tpQ==
 
 "@iarna/toml@2.2.3":
   version "2.2.3"