diff --git a/src/tools/compiletest/src/runtest/rustdoc_json.rs b/src/tools/compiletest/src/runtest/rustdoc_json.rs
index 6cb0c2a040535..89e9f31688379 100644
--- a/src/tools/compiletest/src/runtest/rustdoc_json.rs
+++ b/src/tools/compiletest/src/runtest/rustdoc_json.rs
@@ -18,8 +18,6 @@ impl TestCx<'_> {
             self.fatal_proc_rec("rustdoc failed!", &proc_res);
         }
 
-        let mut json_out = out_dir.join(self.testpaths.file.file_stem().unwrap());
-        json_out.set_extension("json");
         let res = self.run_command_to_procres(
             Command::new(self.config.jsondocck_path.as_ref().unwrap())
                 .arg("--doc-dir")