diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index d5502a9..6076b86 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -1865,6 +1865,26 @@
 //#define MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH
 
 /**
+ * \def MBEDTLS_TEST_HOOKS
+ *
+ * Enable features for invasive testing such as introspection functions and
+ * hooks for fault injection. This enables additional unit tests.
+ *
+ * Merely enabling this feature should not change the behavior of the product.
+ * It only adds new code, and new branching points where the default behavior
+ * is the same as when this feature is disabled.
+ * However, this feature increases the attack surface: there is an added
+ * risk of vulnerabilities, and more gadgets that can make exploits easier.
+ * Therefore this feature must never be enabled in production.
+ *
+ * See `docs/architecture/testing/mbed-crypto-invasive-testing.md` for more
+ * information.
+ *
+ * Uncomment to enable invasive tests.
+ */
+//#define MBEDTLS_TEST_HOOKS
+
+/**
  * \def MBEDTLS_THREADING_ALT
  *
  * Provide your own alternate threading implementation.
diff --git a/library/version_features.c b/library/version_features.c
index d16ad1b..7ecde21 100644
--- a/library/version_features.c
+++ b/library/version_features.c
@@ -555,6 +555,9 @@
 #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
     "MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH",
 #endif /* MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH */
+#if defined(MBEDTLS_TEST_HOOKS)
+    "MBEDTLS_TEST_HOOKS",
+#endif /* MBEDTLS_TEST_HOOKS */
 #if defined(MBEDTLS_THREADING_ALT)
     "MBEDTLS_THREADING_ALT",
 #endif /* MBEDTLS_THREADING_ALT */
diff --git a/programs/test/query_config.c b/programs/test/query_config.c
index bd3f638..27c5d0d 100644
--- a/programs/test/query_config.c
+++ b/programs/test/query_config.c
@@ -1522,6 +1522,14 @@
     }
 #endif /* MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH */
 
+#if defined(MBEDTLS_TEST_HOOKS)
+    if( strcmp( "MBEDTLS_TEST_HOOKS", config ) == 0 )
+    {
+        MACRO_EXPANSION_TO_STR( MBEDTLS_TEST_HOOKS );
+        return( 0 );
+    }
+#endif /* MBEDTLS_TEST_HOOKS */
+
 #if defined(MBEDTLS_THREADING_ALT)
     if( strcmp( "MBEDTLS_THREADING_ALT", config ) == 0 )
     {