diff --git a/library/pkparse.c b/library/pkparse.c
index 3f3d558..31339c1 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -1040,7 +1040,16 @@
         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_VERSION, ret ) );
 
     if( ( ret = pk_get_pk_alg( &p, end, &pk_alg, &params ) ) != 0 )
-        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
+    {
+        if( ret >= -0x007F )
+        {
+            return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );
+        }
+        else
+        {
+            return ret;
+        }
+    }
 
     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
         return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret ) );