diff --git a/dlls/wined3d/arb_program_shader.c b/dlls/wined3d/arb_program_shader.c
index b1837041293..de32587050d 100644
--- a/dlls/wined3d/arb_program_shader.c
+++ b/dlls/wined3d/arb_program_shader.c
@@ -226,7 +226,7 @@ struct recorded_instruction
 
 struct shader_arb_ctx_priv
 {
-    char addr_reg[20];
+    char addr_reg[50];
     enum
     {
         /* plain GL_ARB_vertex_program or GL_ARB_fragment_program */