diff --git a/CHANGELOG.md b/CHANGELOG.md
index 82f3b31b..db0b73db 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,11 @@
+# 3.12.0 (2020-01-01)
+
+* Add support for TypeScript assertion signature syntax, other parser
+  improvements. ([#485], [#487])
+* Implement optional chaining and nullish coalescing.
+  ([#488], [#490], [#492], [#496], [#497], [#498],
+  [tech plan](https://github.com/alangpierce/sucrase/wiki/Sucrase-Optional-Chaining-and-Nullish-Coalescing-Technical-Plan))
+
 # 3.11.0 (2019-12-22)
 
 * Add runtime validation for options. ([#468])
@@ -239,3 +247,14 @@
 [#440]: https://github.com/alangpierce/sucrase/pull/440
 [#441]: https://github.com/alangpierce/sucrase/pull/441
 [#443]: https://github.com/alangpierce/sucrase/pull/443
+[#448]: https://github.com/alangpierce/sucrase/pull/448
+[#463]: https://github.com/alangpierce/sucrase/pull/463
+[#468]: https://github.com/alangpierce/sucrase/pull/468
+[#485]: https://github.com/alangpierce/sucrase/pull/485
+[#487]: https://github.com/alangpierce/sucrase/pull/487
+[#488]: https://github.com/alangpierce/sucrase/pull/488
+[#490]: https://github.com/alangpierce/sucrase/pull/490
+[#492]: https://github.com/alangpierce/sucrase/pull/492
+[#496]: https://github.com/alangpierce/sucrase/pull/496
+[#497]: https://github.com/alangpierce/sucrase/pull/497
+[#498]: https://github.com/alangpierce/sucrase/pull/498
diff --git a/package.json b/package.json
index a4601618..b2673ad1 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sucrase",
-  "version": "3.11.0",
+  "version": "3.12.0",
   "description": "Super-fast alternative to Babel for when you can target modern JS runtimes",
   "author": "Alan Pierce <alangpierce@gmail.com>",
   "license": "MIT",
@@ -70,7 +70,7 @@
     "mocha": "^6.2.2",
     "nyc": "^14.1.1",
     "prettier": "^1.19.1",
-    "sucrase": "^3.11.0",
+    "sucrase": "^3.12.0",
     "test262-harness": "^6.5.0",
     "ts-interface-builder": "^0.2.1",
     "tslint": "^5.20.1",
diff --git a/website/package.json b/website/package.json
index 50f29a5c..23efeca2 100644
--- a/website/package.json
+++ b/website/package.json
@@ -37,7 +37,7 @@
     "react-monaco-editor": "^0.32.1",
     "react-virtualized": "^9.21.1",
     "style-loader": "^1.0.0",
-    "sucrase": "^3.11.0",
+    "sucrase": "^3.12.0",
     "tslint": "^5.20.1",
     "typescript": "^3.7.2",
     "url-loader": "^2.2.0",
diff --git a/website/yarn.lock b/website/yarn.lock
index 9960c8a1..3aef1971 100644
--- a/website/yarn.lock
+++ b/website/yarn.lock
@@ -6289,10 +6289,10 @@ style-loader@^1.0.0:
     loader-utils "^1.2.3"
     schema-utils "^2.0.1"
 
-sucrase@^3.11.0:
-  version "3.11.0"
-  resolved "https://registry.yarnpkg.com/sucrase/-/sucrase-3.11.0.tgz#8d5eeeb38af5c376de906065fa145ba786af5bb8"
-  integrity sha512-vzaNQWMZGNNIOONwBGkwoVPk/haP8TLK0SRTxL/FvuIoiHzDgySBTReTLaOYLAcv4OXvyU3KddLreDvR/bABLA==
+sucrase@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/sucrase/-/sucrase-3.12.0.tgz#1983c8fdf0ac901e8db68917fe76860cce7c1b97"
+  integrity sha512-GHttbEnUlGt3O7oQ7NHV7NCrAmGnAsDb5ar+FUi7hb6oivoF20qokQ1jw2Nv2tCG+VqxF7P+hPavjMXv61oKdA==
   dependencies:
     commander "^4.0.0"
     lines-and-columns "^1.1.6"
diff --git a/yarn.lock b/yarn.lock
index 9c11a20a..e649c4ec 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3516,10 +3516,10 @@ strip-json-comments@^3.0.1:
   resolved "https://registry.yarnpkg.com/strip-json-comments/-/strip-json-comments-3.0.1.tgz#85713975a91fb87bf1b305cca77395e40d2a64a7"
   integrity sha512-VTyMAUfdm047mwKl+u79WIdrZxtFtn+nBxHeb844XBQ9uMNTuTHdx2hc5RiAJYqwTj3wc/xe5HLSdJSkJ+WfZw==
 
-sucrase@^3.11.0:
-  version "3.11.0"
-  resolved "https://registry.yarnpkg.com/sucrase/-/sucrase-3.11.0.tgz#8d5eeeb38af5c376de906065fa145ba786af5bb8"
-  integrity sha512-vzaNQWMZGNNIOONwBGkwoVPk/haP8TLK0SRTxL/FvuIoiHzDgySBTReTLaOYLAcv4OXvyU3KddLreDvR/bABLA==
+sucrase@^3.12.0:
+  version "3.12.0"
+  resolved "https://registry.yarnpkg.com/sucrase/-/sucrase-3.12.0.tgz#1983c8fdf0ac901e8db68917fe76860cce7c1b97"
+  integrity sha512-GHttbEnUlGt3O7oQ7NHV7NCrAmGnAsDb5ar+FUi7hb6oivoF20qokQ1jw2Nv2tCG+VqxF7P+hPavjMXv61oKdA==
   dependencies:
     commander "^4.0.0"
     lines-and-columns "^1.1.6"