diff -rauN nfs-utils-2.3.4/configure.ac nfs-utils-2.3.4-rpcgen-missing-prototype-patch/configure.ac
--- nfs-utils-2.3.4/configure.ac	2019-05-10 21:09:49.000000000 +0200
+++ nfs-utils-2.3.4-rpcgen-missing-prototype-patch/configure.ac	2019-05-23 12:02:26.639999948 +0200
@@ -578,7 +578,7 @@
  -Wall \
  -Wextra \
  $rpcgen_cflags \
- -Werror=missing-prototypes \
+ -Wmissing-prototypes \
  -Werror=missing-declarations \
  -Werror=format=2 \
  -Werror=undef \