diff --git a/flake.lock b/flake.lock
index 9848cb996..0a5f76db7 100644
--- a/flake.lock
+++ b/flake.lock
@@ -6,4 +6,4 @@
         }
     },
     "version": 1
-}
\ No newline at end of file
+}
diff --git a/src/libexpr/primops/flake.cc b/src/libexpr/primops/flake.cc
index 5e732b362..1d409105f 100644
--- a/src/libexpr/primops/flake.cc
+++ b/src/libexpr/primops/flake.cc
@@ -121,7 +121,7 @@ void writeLockFile(const LockFile & lockFile, const Path & path)
     for (auto & x : lockFile.flakeEntries)
         json["requires"][x.first.to_string()] = flakeEntryToJson(x.second);
     createDirs(dirOf(path));
-    writeFile(path, json.dump(4)); // '4' = indentation in json file
+    writeFile(path, json.dump(4) + "\n"); // '4' = indentation in json file
 }
 
 std::shared_ptr<FlakeRegistry> getGlobalRegistry()