diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index edde05d0ea4..6616c76f9a5 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -7526,7 +7526,9 @@ let
 
   openbr = callPackage ../development/libraries/openbr { };
 
-  opencascade = callPackage ../development/libraries/opencascade { };
+  opencascade = callPackage ../development/libraries/opencascade {
+    tcl = tcl-8_5;
+  };
 
   opencascade_6_5 = callPackage ../development/libraries/opencascade/6.5.nix {
     automake = automake111x;