diff --git a/OpenCL/m09100.cl b/OpenCL/m09100.cl
index 92a86c0e0..293f9a1f6 100644
--- a/OpenCL/m09100.cl
+++ b/OpenCL/m09100.cl
@@ -89,7 +89,7 @@ static void lotus_mix (u32 *in, __local u32 s_lotus_magic_table[256])
   }
 }
 
-static void lotus_transform_password (u32 *in, u32 *out, __local u32 s_lotus_magic_table[256])
+static void lotus_transform_password (u32 in[4], u32 out[4], __local u32 s_lotus_magic_table[256])
 {
   u32 t = out[3] >> 24;