diff --git a/contrib/osx/README.md b/contrib/osx/README.md
index fdba1913f..41ad97c13 100644
--- a/contrib/osx/README.md
+++ b/contrib/osx/README.md
@@ -13,6 +13,9 @@ This needs to be done on a system running macOS or OS X. We use El Capitan (10.1
 on High Sierra (or later)
 makes the binaries [incompatible with older versions](https://github.com/pyinstaller/pyinstaller/issues/1191).
 
+Another factor for the minimum supported macOS version is the
+[bundled Qt version](https://github.com/spesmilo/electrum/issues/3685).
+
 Before starting, make sure that the Xcode command line tools are installed (e.g. you have `git`).
 
 #### 1.1a Get Xcode