diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 9a7f6a2fb5d..c0d2f15dcde 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -10848,7 +10848,9 @@ in
 
   gpm-ncurses = self.gpm.override { inherit ncurses; };
 
-  gradm = callPackage ../os-specific/linux/gradm { };
+  gradm = callPackage ../os-specific/linux/gradm {
+    flex = flex_2_5_35;
+  };
 
   hdparm = callPackage ../os-specific/linux/hdparm { };