diff --git a/HACKING.md b/HACKING.md
index 7961ca93..7c702ea6 100644
--- a/HACKING.md
+++ b/HACKING.md
@@ -6,7 +6,7 @@ work on CosmJS, i.e. modify it. It is not intended for users of CosmJS.
 ## Prerequisite
 
 - A UNIX-like development environment
-- Node.js 10+, Docker and yarn
+- Node.js 12+, Docker and yarn
 - `sha256sum`, which you
   [can get on macOS as well](https://unix.stackexchange.com/questions/426837/no-sha256sum-in-macos)
 
diff --git a/README.md b/README.md
index 20513ba4..9fee28cb 100644
--- a/README.md
+++ b/README.md
@@ -77,7 +77,7 @@ optipng docs/cosmjs-tree*.png
 
 Currently the codebase supports the following runtime environments:
 
-1. Node.js 10+
+1. Node.js 12+
 2. Modern browsers (Chromium/Firefox/Safari, no Internet Explorer or
    [Edge Spartan](https://en.wikipedia.org/wiki/Microsoft_Edge#Development))
 3. Browser extensions (Chromium/Firefox)