diff --git a/pkgs/by-name/li/librttopo/package.nix b/pkgs/by-name/li/librttopo/package.nix
index 339f618cd88c..12ea18a9c3a5 100644
--- a/pkgs/by-name/li/librttopo/package.nix
+++ b/pkgs/by-name/li/librttopo/package.nix
@@ -27,11 +27,14 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [
     autoreconfHook
     validatePkgConfig
-    geos # for geos-config
   ];
 
   buildInputs = [ geos ];
 
+  configureFlags = [
+    "--with-geosconfig=${lib.getExe' (lib.getDev geos) "geos-config"}"
+  ];
+
   enableParallelBuilding = true;
 
   meta = with lib; {