diff --git a/dlls/d3dx9_36/preshader.c b/dlls/d3dx9_36/preshader.c
index 126f3cc08b3..e9c8387aef9 100644
--- a/dlls/d3dx9_36/preshader.c
+++ b/dlls/d3dx9_36/preshader.c
@@ -368,7 +368,7 @@ static void regstore_set_modified(struct d3dx_regstore *rs, unsigned int table,
             get_reg_offset(table, start_offset + count - 1));
 }
 
-static void regstore_set_values(struct d3dx_regstore *rs, unsigned int table, void *data,
+static void regstore_set_values(struct d3dx_regstore *rs, unsigned int table, const void *data,
         unsigned int start_offset, unsigned int count)
 {
     if (!count)