diff --git a/README.md b/README.md
index d42fe9edfb..5724308185 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@
 About
 -----
 
-- **Important**: This is Lean 3.19.0c, a fork of Lean 3 maintained and updated by the Lean community. The last official release of Lean 3.x was Lean 3.4.2, which can be found [here](https://github.com/leanprover/lean). The Lean developers are currently developing [Lean 4](https://github.com/leanprover/lean4).
+- **Important**: This is Lean 3.20.0c, a fork of Lean 3 maintained and updated by the Lean community. The last official release of Lean 3.x was Lean 3.4.2, which can be found [here](https://github.com/leanprover/lean). The Lean developers are currently developing [Lean 4](https://github.com/leanprover/lean4).
 - [Lean Homepage](http://leanprover.github.io)
 - [Lean Prover Community Homepage](https://leanprover-community.github.io)
 - [Theorem Proving in Lean](https://leanprover.github.io/theorem_proving_in_lean/index.html)
diff --git a/doc/changes.md b/doc/changes.md
index d50eff91cb..ea7bb65e26 100644
--- a/doc/changes.md
+++ b/doc/changes.md
@@ -1,3 +1,18 @@
+3.20.0c (9 September 2020)
+--------------------------
+
+Features:
+- Options are refreshed when the simplifier is entered. (#456)
+- JSON support for widgets (#453)
+- More definition and theorem docstrings (#463)
+
+Bug fixes:
+- Typeclass args for `monad_state_trans` were flipped. (#461)
+- `resolve_constant` now handles `parameters` correctly. (#462)
+
+Changes:
+- Remove `nat.pow` from the core library (#457)
+
 3.19.0c (27 August 2020)
 ------------------------
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a29652cd36..8b27b94701 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -4,7 +4,7 @@ if ((${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 3.1) OR (${CMAKE_MAJO
 endif()
 project(LEAN CXX C)
 set(LEAN_VERSION_MAJOR 3)
-set(LEAN_VERSION_MINOR 19)
+set(LEAN_VERSION_MINOR 20)
 set(LEAN_VERSION_PATCH 0)
 set(LEAN_VERSION_IS_RELEASE 1)  # This number is 1 in the release revision, and 0 otherwise.
 set(LEAN_SPECIAL_VERSION_DESC "" CACHE STRING "Additional version description like 'nightly-2018-03-11'")