diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 66e6208223f..d17bd889df5 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -17273,7 +17273,9 @@ in
 
   scilab-bin = callPackage ../applications/science/math/scilab-bin {};
 
-  scotch = callPackage ../applications/science/math/scotch { };
+  scotch = callPackage ../applications/science/math/scotch {
+    flex = flex_2_5_35;
+  };
 
   msieve = callPackage ../applications/science/math/msieve { };