diff --git a/tests/include/test/psa_exercise_key.h b/tests/include/test/psa_exercise_key.h
index b0e318144..b1e285a96 100644
--- a/tests/include/test/psa_exercise_key.h
+++ b/tests/include/test/psa_exercise_key.h
@@ -16,7 +16,10 @@
 
 #if defined(MBEDTLS_PK_C)
 #include <mbedtls/pk.h>
-#endif
+#if defined(MBEDTLS_PK_HAVE_PRIVATE_HEADER)
+#include <mbedtls/private/pk_private.h>
+#endif /* MBEDTLS_PK_HAVE_PRIVATE_HEADER */
+#endif /* MBEDTLS_PK_C */
 
 /** \def KNOWN_SUPPORTED_HASH_ALG
  *