diff --git a/cibuildwheel/pyodide.py b/cibuildwheel/pyodide.py
index 3b721a10a..7309e79fa 100644
--- a/cibuildwheel/pyodide.py
+++ b/cibuildwheel/pyodide.py
@@ -21,6 +21,7 @@
     BuildSelector,
     call,
     combine_constraints,
+    copy_test_sources,
     download,
     ensure_node,
     extract_zip,
@@ -381,7 +382,15 @@ def build(options: Options, tmp_path: Path) -> None:
 
                 test_cwd = identifier_tmp_dir / "test_cwd"
                 test_cwd.mkdir(exist_ok=True)
-                (test_cwd / "test_fail.py").write_text(test_fail_cwd_file.read_text())
+                if build_options.test_sources:
+                    copy_test_sources(
+                        build_options.test_sources,
+                        build_options.package_dir,
+                        test_cwd,
+                    )
+                else:
+                    # There are no test sources. Copy the test safety file.
+                    (test_cwd / "test_fail.py").write_text(test_fail_cwd_file.read_text())
 
                 shell(test_command_prepared, cwd=test_cwd, env=virtualenv_env)