diff --git a/pkgs/applications/science/misc/gplates/default.nix b/pkgs/applications/science/misc/gplates/default.nix
index 7cbf37fcaf8a..835c66c3251f 100644
--- a/pkgs/applications/science/misc/gplates/default.nix
+++ b/pkgs/applications/science/misc/gplates/default.nix
@@ -14,13 +14,15 @@
 , libGLU
 , mpfr
 , proj
-, python3
+# build with Python 3.10 fails, because boost <= 1.78 can't find
+# pythons with double digits in minor versions, like X.YZ
+, python39
 , qtxmlpatterns
 , qwt
 }:
 
 let
-  python = python3.withPackages (ps: with ps; [
+  python = python39.withPackages (ps: with ps; [
     numpy
   ]);
   boost' = boost.override {