diff --git a/library/psa_its_file.c b/library/psa_its_file.c
index c4782cd..bec3231 100644
--- a/library/psa_its_file.c
+++ b/library/psa_its_file.c
@@ -184,6 +184,11 @@
                           const void *p_data,
                           psa_storage_create_flags_t create_flags )
 {
+    if( uid == 0 )
+    {
+        return (PSA_ERROR_INVALID_HANDLE);
+    }
+
     psa_status_t status = PSA_ERROR_STORAGE_FAILURE;
     char filename[PSA_ITS_STORAGE_FILENAME_LENGTH];
     FILE *stream = NULL;