diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 40e9e57..2fd70c6 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -736,6 +736,11 @@
     TEST_EQUAL( mbedtls_asn1_get_tag( p, end, &len,
                                       MBEDTLS_ASN1_INTEGER ),
                 0 );
+
+    /* Check if the retrieved length doesn't extend the actual buffer's size.
+     * It is assumed here, that end >= p, which validates casting to size_t. */
+    TEST_ASSERT( len <= (size_t)( end - *p) );
+
     /* Tolerate a slight departure from DER encoding:
      * - 0 may be represented by an empty string or a 1-byte string.
      * - The sign bit may be used as a value bit. */