diff --git a/libs/vkd3d-shader/tpf.c b/libs/vkd3d-shader/tpf.c
index 7700a2d9..5bbfa4d1 100644
--- a/libs/vkd3d-shader/tpf.c
+++ b/libs/vkd3d-shader/tpf.c
@@ -3474,8 +3474,7 @@ static void write_sm4_rdef(struct hlsl_ctx *ctx, struct dxbc_writer *dxbc)
 
         LIST_FOR_EACH_ENTRY(var, &ctx->extern_vars, struct hlsl_ir_var, extern_entry)
         {
-            if (var->is_uniform && var->buffer == cbuffer
-                    && var->data_type->class != HLSL_CLASS_OBJECT)
+            if (var->is_uniform && var->buffer == cbuffer && var->data_type->reg_size[HLSL_REGSET_NUMERIC])
                 ++var_count;
         }
 
@@ -3509,8 +3508,7 @@ static void write_sm4_rdef(struct hlsl_ctx *ctx, struct dxbc_writer *dxbc)
 
         LIST_FOR_EACH_ENTRY(var, &ctx->extern_vars, struct hlsl_ir_var, extern_entry)
         {
-            if (var->is_uniform && var->buffer == cbuffer
-                    && var->data_type->class != HLSL_CLASS_OBJECT)
+            if (var->is_uniform && var->buffer == cbuffer && var->data_type->reg_size[HLSL_REGSET_NUMERIC])
             {
                 uint32_t flags = 0;
 
@@ -3537,8 +3535,7 @@ static void write_sm4_rdef(struct hlsl_ctx *ctx, struct dxbc_writer *dxbc)
         j = 0;
         LIST_FOR_EACH_ENTRY(var, &ctx->extern_vars, struct hlsl_ir_var, extern_entry)
         {
-            if (var->is_uniform && var->buffer == cbuffer
-                    && var->data_type->class != HLSL_CLASS_OBJECT)
+            if (var->is_uniform && var->buffer == cbuffer && var->data_type->reg_size[HLSL_REGSET_NUMERIC])
             {
                 const unsigned int var_size = (profile->major_version >= 5 ? 10 : 6);
                 size_t var_offset = vars_start + j * var_size * sizeof(uint32_t);