diff --git a/tests/call_arg_eval_context.fl b/tests/call_arg_eval_context.fl
new file mode 100644
index 0000000..3cf2ce1
--- /dev/null
+++ b/tests/call_arg_eval_context.fl
@@ -0,0 +1,9 @@
+# Regression test.
+# When calling a function that is defined in a different source file, the context's source could be switched to the source file of the function being called before the argument expressions are evaluated.
+# This would cause these evaluations to use the wrong source file.
+
+# TODO rename this
+
+import .tests.call_arg_eval_context_helper
+
+assert function("zonnebloemgranen") == "zonnebloemgranen"
diff --git a/tests/call_arg_eval_context_helper.fl b/tests/call_arg_eval_context_helper.fl
new file mode 100644
index 0000000..b97f5a9
--- /dev/null
+++ b/tests/call_arg_eval_context_helper.fl
@@ -0,0 +1,3 @@
+fn function(x) {
+	return x
+}