diff --git a/tools/widl/client.c b/tools/widl/client.c
index 7e1e70b6a2f..eb1ade2bb7e 100644
--- a/tools/widl/client.c
+++ b/tools/widl/client.c
@@ -186,6 +186,16 @@ static void write_function_stubs(type_t *iface, unsigned int *proc_offset)
         indent--;
         fprintf(client, "\n");
 
+        if (is_attr(def->attrs, ATTR_IDEMPOTENT) || is_attr(def->attrs, ATTR_BROADCAST))
+        {
+            print_client("_RpcMessage.RpcFlags = ( RPC_NCA_FLAGS_DEFAULT ");
+            if (is_attr(def->attrs, ATTR_IDEMPOTENT))
+                fprintf(client, "| RPC_NCA_FLAGS_IDEMPOTENT ");
+            if (is_attr(def->attrs, ATTR_BROADCAST))
+                fprintf(client, "| RPC_NCA_FLAGS_BROADCAST ");
+            fprintf(client, ");\n\n");
+        }
+
         if (implicit_handle)
         {
             print_client("_Handle = %s;\n", implicit_handle);
diff --git a/tools/widl/parser.y b/tools/widl/parser.y
index 929d95c5570..81eacbad793 100644
--- a/tools/widl/parser.y
+++ b/tools/widl/parser.y
@@ -457,6 +457,7 @@ attribute:					{ $$ = NULL; }
 	| tASYNC				{ $$ = make_attr(ATTR_ASYNC); }
 	| tAUTOHANDLE				{ $$ = make_attr(ATTR_AUTO_HANDLE); }
 	| tBINDABLE				{ $$ = make_attr(ATTR_BINDABLE); }
+	| tBROADCAST				{ $$ = make_attr(ATTR_BROADCAST); }
 	| tCALLAS '(' ident ')'			{ $$ = make_attrp(ATTR_CALLAS, $3); }
 	| tCASE '(' expr_list_const ')'		{ $$ = make_attrp(ATTR_CASE, $3); }
 	| tCONTEXTHANDLE			{ $$ = make_attrv(ATTR_CONTEXTHANDLE, 0); }
@@ -2154,6 +2155,7 @@ struct allowed_attr allowed_attr[] =
     /* ATTR_ASYNC */            { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, "async" },
     /* ATTR_AUTO_HANDLE */      { 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, "auto_handle" },
     /* ATTR_BINDABLE */         { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, "bindable" },
+    /* ATTR_BROADCAST */        { 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, "broadcast" },
     /* ATTR_CALLAS */           { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, "call_as" },
     /* ATTR_CALLCONV */         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL },
     /* ATTR_CASE */             { 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, "case" },
diff --git a/tools/widl/widltypes.h b/tools/widl/widltypes.h
index 348833733b2..d046447412b 100644
--- a/tools/widl/widltypes.h
+++ b/tools/widl/widltypes.h
@@ -69,6 +69,7 @@ enum attr_type
     ATTR_ASYNC,
     ATTR_AUTO_HANDLE,
     ATTR_BINDABLE,
+    ATTR_BROADCAST,
     ATTR_CALLAS,
     ATTR_CALLCONV, /* calling convention pseudo-attribute */
     ATTR_CASE,