diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index b9da59935564..086e8bee32c5 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1695,7 +1695,7 @@ with pkgs;
 
   dtach = callPackage ../tools/misc/dtach { };
 
-  dtc = callPackage ../development/compilers/dtc { flex = flex_2_6_1; };
+  dtc = callPackage ../development/compilers/dtc { };
 
   dub = callPackage ../development/tools/build-managers/dub { };