diff --git a/src/version.c b/src/version.c
index 154b7e3..f273a15 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4178,
+/**/
     4177,
 /**/
     4176,
diff --git a/src/vim9cmds.c b/src/vim9cmds.c
index 83ff699..27322df 100644
--- a/src/vim9cmds.c
+++ b/src/vim9cmds.c
@@ -2196,7 +2196,10 @@
 
     if (*p != NUL && *p != '|' && *p != '\n')
     {
-	if (cctx->ctx_ufunc->uf_ret_type->tt_type == VAR_VOID)
+	// For a lambda, "return expr" is always used, also when "expr" results
+	// in a void.
+	if (cctx->ctx_ufunc->uf_ret_type->tt_type == VAR_VOID
+		&& (cctx->ctx_ufunc->uf_flags & FC_LAMBDA) == 0)
 	{
 	    emsg(_(e_returning_value_in_function_without_return_type));
 	    return NULL;