diff --git a/pkgs/by-name/ru/rustdesk-flutter/package.nix b/pkgs/by-name/ru/rustdesk-flutter/package.nix
index 3ff05d808baa..0c6ecb9a6bd3 100644
--- a/pkgs/by-name/ru/rustdesk-flutter/package.nix
+++ b/pkgs/by-name/ru/rustdesk-flutter/package.nix
@@ -163,8 +163,11 @@ flutter319.buildFlutterApplication rec {
   patches = [ ./make-build-reproducible.patch ];
 
   postPatch = ''
-    substituteInPlace $cargoDepsCopy/libappindicator-sys-*/src/lib.rs \
-      --replace-fail "libayatana-appindicator3.so.1" "${lib.getLib libayatana-appindicator}/lib/libayatana-appindicator3.so.1"
+    if [ $cargoDepsCopy ]; then # That will be inherited to buildDartPackage and it doesn't have cargoDepsCopy
+      substituteInPlace $cargoDepsCopy/libappindicator-sys-*/src/lib.rs \
+        --replace-fail "libayatana-appindicator3.so.1" "${lib.getLib libayatana-appindicator}/lib/libayatana-appindicator3.so.1"
+    fi
+
     substituteInPlace ../Cargo.toml --replace-fail ", \"staticlib\", \"rlib\"" ""
     # The supplied Cargo.lock doesn't work with our fetcher so copy over the fixed version
     cp ${./Cargo.lock} ../Cargo.lock