diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index ada05947688f..eef806d93839 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -5108,11 +5108,10 @@ with pkgs;
   # The GCC used to build libc for the target platform. Normal gccs will be
   # built with, and use, that cross-compiled libc.
   gccWithoutTargetLibc =
-    assert stdenv.targetPlatform != stdenv.hostPlatform;
     let
       libc1 = binutilsNoLibc.libc;
     in
-    wrapCCWith {
+    (wrapCCWith {
       cc = gccFun {
         # copy-pasted
         inherit noSysDirs;
@@ -5138,7 +5137,14 @@ with pkgs;
       bintools = binutilsNoLibc;
       libc = libc1;
       extraPackages = [ ];
-    };
+    }).overrideAttrs
+      (prevAttrs: {
+        meta = prevAttrs.meta // {
+          badPlatforms =
+            (prevAttrs.meta.badPlatforms or [ ])
+            ++ lib.optionals (stdenv.targetPlatform == stdenv.hostPlatform) [ stdenv.hostPlatform.system ];
+        };
+      });
 
   inherit (callPackage ../development/compilers/gcc/all.nix { inherit noSysDirs; })
     gcc9