diff --git a/pkgs/servers/gpm/default.nix b/pkgs/servers/gpm/default.nix
index 66c6607e6472..76358404e970 100644
--- a/pkgs/servers/gpm/default.nix
+++ b/pkgs/servers/gpm/default.nix
@@ -43,7 +43,7 @@ stdenv.mkDerivation rec {
   configureFlags = [
     "--sysconfdir=/etc"
     "--localstatedir=/var"
-    (if ncurses == null then "--without-curses" else "--with-curses")
+    (if withNcurses then "--with-curses" else "--without-curses")
   ];
 
   enableParallelBuilding = true;
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 9cbf99add1d9..0a6644190477 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -23612,7 +23612,7 @@ with pkgs;
   };
 
   gpm = callPackage ../servers/gpm {
-    ncurses = null;  # Keep curses disabled for lack of value
+    withNcurses = false; # Keep curses disabled for lack of value
 
     # latest 6.8 mysteriously fails to parse '@headings single':
     #   https://lists.gnu.org/archive/html/bug-texinfo/2021-09/msg00011.html