diff --git a/pkgs/development/coq-modules/reglang/default.nix b/pkgs/development/coq-modules/reglang/default.nix
index fd5a37c677e2..325b909d45e4 100644
--- a/pkgs/development/coq-modules/reglang/default.nix
+++ b/pkgs/development/coq-modules/reglang/default.nix
@@ -5,14 +5,16 @@ mkCoqDerivation {
 
   releaseRev = v: "v${v}";
 
+  release."1.2.1".sha256 = "sha256-giCRK8wzpVVzXAkFAieQDWqSsP7upSJSUUHkwG4QqO4=";
   release."1.2.0".sha256 = "sha256-gSqQ7D2HLwM4oYopTWkMFYfYXxsH/7VxI3AyrLwNf3o=";
   release."1.1.3".sha256 = "sha256-kaselYm8K0JBsTlcI6K24m8qpv8CZ9+VNDJrOtFaExg=";
   release."1.1.2".sha256 = "sha256-SEnMilLNxh6a3oiDNGLaBr8quQ/nO2T9Fwdf/1il2Yk=";
 
   inherit version;
   defaultVersion = with lib.versions; lib.switch [ coq.coq-version mathcomp.version ] [
-    { cases = [ (range "8.16" "8.18") (isGe "2.0.0") ]; out = "1.2.0"; }
-    { cases = [ (range "8.10" "8.18") (isLt "2.0.0") ]; out = "1.1.3"; }
+    { cases = [ (range "8.16" "8.19") (isGe "2.0.0") ]; out = "1.2.1"; }
+    { cases = [ (range "8.16" "8.18") (range "2.0.0" "2.1.0") ]; out = "1.2.0"; }
+    { cases = [ (range "8.10" "8.19") (isLt "2.0.0") ]; out = "1.1.3"; }
   ] null;