diff --git a/include/common/test_helpers.h b/include/common/test_helpers.h
index f9d41dd..a6ec074 100644
--- a/include/common/test_helpers.h
+++ b/include/common/test_helpers.h
@@ -267,4 +267,19 @@
 test_result_t map_test_unmap(const map_args_unmap_t *args,
 			     test_function_arg_t test);
 
+/*
+ * Helper function to set TFTF global mailbox for SPM related tests.
+ * This function should be invoked by the first TFTF test that requires
+ * RX and/or TX buffers.
+ */
+void set_tftf_mailbox(const struct mailbox_buffers *mb);
+
+/*
+ * Helper function to get TFTF global mailbox for SPM related tests.
+ * This function should be called by all tests that require access to RX or TX
+ * buffers, after the function 'set_tftf_mailbox' has been used by the first
+ * test to rely on RX and TX buffers.
+ */
+bool get_tftf_mailbox(struct mailbox_buffers *mb);
+
 #endif /* __TEST_HELPERS_H__ */