diff --git a/package.json b/package.json
index d327019e..4c7c458b 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
   "dependencies": {
     "@babel/parser": "^7.13.15",
     "@babel/traverse": "^7.13.17",
-    "@glimmer/syntax": "^0.80.0",
+    "@glimmer/syntax": "^0.84.0",
     "chalk": "^4.1.1",
     "emblem": "^0.12.1",
     "esm": "^3.2.25",
diff --git a/yarn.lock b/yarn.lock
index 8b56459f..91cb6e0d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -337,30 +337,30 @@
   resolved "https://registry.yarnpkg.com/@glimmer/env/-/env-0.1.7.tgz#fd2d2b55a9029c6b37a6c935e8c8871ae70dfa07"
   integrity sha1-/S0rVakCnGs3psk16MiHGucN+gc=
 
-"@glimmer/interfaces@0.80.3":
-  version "0.80.3"
-  resolved "https://registry.yarnpkg.com/@glimmer/interfaces/-/interfaces-0.80.3.tgz#c7c866376d73b9c4e4282e9056c6798e84ce7331"
-  integrity sha512-38PVcR7uFdFdJnqDNhLMbaluZhJezdwRAJCTkwk/AxlC2bGa6iCv2GDQhErXp1qr26gyO7dt37gbtwLojBDauA==
+"@glimmer/interfaces@0.84.0":
+  version "0.84.0"
+  resolved "https://registry.yarnpkg.com/@glimmer/interfaces/-/interfaces-0.84.0.tgz#fa5cb7189910c853d473db19133d2180d813c0b7"
+  integrity sha512-+2clm2821gP+LiA4w1GOQtjgLDoqFOYVw3uwTvmzKGislR5lzC9s0la3W7NCqYwApv2aeZry4CJ6um6/Q46mYw==
   dependencies:
     "@simple-dom/interface" "^1.4.0"
 
-"@glimmer/syntax@^0.80.0":
-  version "0.80.3"
-  resolved "https://registry.yarnpkg.com/@glimmer/syntax/-/syntax-0.80.3.tgz#9018469f03c9ad5ee9e14446280f5f6312bdf130"
-  integrity sha512-hACbTpXgNO2l7USDVDUPvXh4Xo9e06sQEyv1QvGn/MK8FKfMkThxOmLrWy/pcEdeePmCMNGMLGgfjG6bO5FCUQ==
+"@glimmer/syntax@^0.84.0":
+  version "0.84.0"
+  resolved "https://registry.yarnpkg.com/@glimmer/syntax/-/syntax-0.84.0.tgz#bf5104fc2be7c853f1e3897dda16a655f6fd7d5f"
+  integrity sha512-TAo1vaO5SPWtstU3XOAeiG5izhlw2v2ASns7f5dwe0hzGPRHPGuatmsVCtw/CS6FH86weboLrOGz0KQwjMaKfQ==
   dependencies:
-    "@glimmer/interfaces" "0.80.3"
-    "@glimmer/util" "0.80.3"
+    "@glimmer/interfaces" "0.84.0"
+    "@glimmer/util" "0.84.0"
     "@handlebars/parser" "~2.0.0"
-    simple-html-tokenizer "^0.5.10"
+    simple-html-tokenizer "^0.5.11"
 
-"@glimmer/util@0.80.3":
-  version "0.80.3"
-  resolved "https://registry.yarnpkg.com/@glimmer/util/-/util-0.80.3.tgz#573e562e20c7c1a869d84095a987d641ea9885d1"
-  integrity sha512-H6u9gPpBrZWfdHAXQyVTsttSJzBfpQ2NWc2Jnh35b7HxPpg0npcLsjIAuba4gHlcsKLwlN42s3O+J8x9weL4gQ==
+"@glimmer/util@0.84.0":
+  version "0.84.0"
+  resolved "https://registry.yarnpkg.com/@glimmer/util/-/util-0.84.0.tgz#a9d3a9471678e5c80470646a70ea54c2cf1f8e2c"
+  integrity sha512-H5OjZXaroV821TLVHXox4t2GICwUA8HdijyAf+wouSfINmm+y4GbbEwoZM9ns8YSZGX7/gG0Z4Znwti0oFbHPw==
   dependencies:
     "@glimmer/env" "0.1.7"
-    "@glimmer/interfaces" "0.80.3"
+    "@glimmer/interfaces" "0.84.0"
     "@simple-dom/interface" "^1.4.0"
 
 "@handlebars/parser@~2.0.0":
@@ -3854,7 +3854,7 @@ signal-exit@^3.0.0, signal-exit@^3.0.2, signal-exit@^3.0.3:
   resolved "https://registry.yarnpkg.com/signal-exit/-/signal-exit-3.0.7.tgz#a9a1767f8af84155114eaabd73f99273c8f59ad9"
   integrity sha512-wnD2ZE+l+SPC/uoS0vXeE9L1+0wuaMqKlfz9AMUo38JsyLSBWSFcHR1Rri62LZc12vLr1gb3jl7iwQhgwpAbGQ==
 
-simple-html-tokenizer@^0.5.10:
+simple-html-tokenizer@^0.5.11:
   version "0.5.11"
   resolved "https://registry.yarnpkg.com/simple-html-tokenizer/-/simple-html-tokenizer-0.5.11.tgz#4c5186083c164ba22a7b477b7687ac056ad6b1d9"
   integrity sha512-C2WEK/Z3HoSFbYq8tI7ni3eOo/NneSPRoPpcM7WdLjFOArFuyXEjAoCdOC3DgMfRyziZQ1hCNR4mrNdWEvD0og==