diff --git a/pkgs/development/libraries/physics/herwig/default.nix b/pkgs/development/libraries/physics/herwig/default.nix
index 69a8c781d5b..0a7e9b4d948 100644
--- a/pkgs/development/libraries/physics/herwig/default.nix
+++ b/pkgs/development/libraries/physics/herwig/default.nix
@@ -28,7 +28,7 @@ stdenv.mkDerivation rec {
   meta = with lib; {
     description = "A multi-purpose particle physics event generator";
     homepage = "https://herwig.hepforge.org/";
-    license = licenses.gpl3;
+    license = licenses.gpl3Only;
     maintainers = with maintainers; [ veprbl ];
     platforms = platforms.unix;
     broken = stdenv.isAarch64; # doesn't compile: ignoring return value of 'FILE* freopen...
diff --git a/pkgs/development/libraries/physics/thepeg/default.nix b/pkgs/development/libraries/physics/thepeg/default.nix
index 031277f8e0c..ed92889b5b2 100644
--- a/pkgs/development/libraries/physics/thepeg/default.nix
+++ b/pkgs/development/libraries/physics/thepeg/default.nix
@@ -22,7 +22,7 @@ stdenv.mkDerivation rec {
   meta = with lib; {
     description = "Toolkit for High Energy Physics Event Generation";
     homepage = "https://herwig.hepforge.org/";
-    license = licenses.gpl3;
+    license = licenses.gpl3Only;
     maintainers = with maintainers; [ veprbl ];
     platforms = platforms.unix;
   };