diff --git a/Makefile b/Makefile
index 74bedae9..8e65603c 100644
--- a/Makefile
+++ b/Makefile
@@ -294,6 +294,7 @@ install::
 scan-build::
 	scan-build $(MAKE) build
 
+
 ########################################################################
 
 ### mx_log.h -----------------------------------------------------------
@@ -361,6 +362,14 @@ ppidcache.h += ppidcache.h
 
 ########################################################################
 
+## parser.tab.o
+
+# Disable "variable 'yynerrs' set but not used" diagnostic which
+# appears with bison-3.4.2 + llvm 15.0.4
+
+parser.tab.o: parser.tab.c parser.tab.h
+	$(call quiet-command,${CC} ${CFLAGS} -Wno-unused-but-set-variable -o $@ -c $<,"     CC $@")
+
 ### mx_getopt.o --------------------------------------------------------
 
 mx_getopt.o: $(mx_getopt.h)