diff --git a/tf-psa-crypto/drivers/builtin/include/mbedtls/config_adjust_test_accelerators.h b/tf-psa-crypto/drivers/builtin/include/mbedtls/config_adjust_test_accelerators.h
index 7b50936dc7..5f25879780 100644
--- a/tf-psa-crypto/drivers/builtin/include/mbedtls/config_adjust_test_accelerators.h
+++ b/tf-psa-crypto/drivers/builtin/include/mbedtls/config_adjust_test_accelerators.h
@@ -38,6 +38,14 @@
 #ifndef MBEDTLS_CONFIG_ADJUST_TEST_ACCELERATORS_H
 #define MBEDTLS_CONFIG_ADJUST_TEST_ACCELERATORS_H
 
+#if !defined(MBEDTLS_CONFIG_FILES_READ)
+#error "Do not include mbedtls/config_adjust_*.h manually! This can lead to problems, " \
+    "up to and including runtime errors such as buffer overflows. " \
+    "If you're trying to fix a complaint from check_config.h, just remove " \
+    "it from your configuration file: since Mbed TLS 3.0, it is included " \
+    "automatically at the right point."
+#endif
+
 #if defined(PSA_CRYPTO_DRIVER_TEST_ALL)
 /* PSA_CRYPTO_DRIVER_TEST_ALL activates test drivers while keeping the
  * built-in implementations active. Normally setting MBEDTLS_PSA_ACCEL_xxx