diff --git a/bin/install-qa-check.d/90gcc-warnings b/bin/install-qa-check.d/90gcc-warnings
index 48c11e4..9703c39 100644
--- a/bin/install-qa-check.d/90gcc-warnings
+++ b/bin/install-qa-check.d/90gcc-warnings
@@ -71,39 +71,43 @@
 			#': warning: missing sentinel in function call'
 			#': warning: not enough variable arguments to fit a sentinel'
 		)
+
+		# join all messages into one grep-expression
+		local joined_msgs
+		printf -v joined_msgs '%s|' "${msgs[@]}"
+		joined_msgs=${joined_msgs%|}
+
 		local abort="no"
-		local i=0
 		local grep_cmd=grep
 		[[ $PORTAGE_LOG_FILE = *.gz ]] && grep_cmd=zgrep
-		while [[ -n ${msgs[${i}]} ]] ; do
-			m=${msgs[$((i++))]}
-			# force C locale to work around slow unicode locales #160234
-			f=$(LC_ALL=C $grep_cmd "${m}" "${PORTAGE_LOG_FILE}")
-			if [[ -n ${f} ]] ; then
-				abort="yes"
-				# for now, don't make this fatal (see bug #337031)
-				#case "$m" in
-				#	": warning: call to .* will always overflow destination buffer") always_overflow=yes ;;
-				#esac
-				if [[ $always_overflow = yes ]] ; then
-					eerror
-					eerror "QA Notice: Package triggers severe warnings which indicate that it"
-					eerror "           may exhibit random runtime failures."
-					eerror
-					eerror "${f}"
-					eerror
-					eerror " Please file a bug about this at http://bugs.gentoo.org/"
-					eerror " with the maintaining herd of the package."
-					eerror
-				else
-					__vecho -ne '\n'
-					eqawarn "QA Notice: Package triggers severe warnings which indicate that it"
-					eqawarn "           may exhibit random runtime failures."
-					eqawarn "${f}"
-					__vecho -ne '\n'
-				fi
+
+		# force C locale to work around slow unicode locales #160234
+		f=$(LC_CTYPE=C LC_COLLATE=C "${grep_cmd}" -E "${joined_msgs}" "${PORTAGE_LOG_FILE}")
+		if [[ -n ${f} ]] ; then
+			abort="yes"
+			# for now, don't make this fatal (see bug #337031)
+			#if [[ ${f} == *'will always overflow destination buffer'* ]]; then
+			#	always_overflow=yes
+			#fi
+			if [[ $always_overflow = yes ]] ; then
+				eerror
+				eerror "QA Notice: Package triggers severe warnings which indicate that it"
+				eerror "           may exhibit random runtime failures."
+				eerror
+				eerror "${f}"
+				eerror
+				eerror " Please file a bug about this at http://bugs.gentoo.org/"
+				eerror " with the maintaining herd of the package."
+				eerror
+			else
+				__vecho -ne '\n'
+				eqawarn "QA Notice: Package triggers severe warnings which indicate that it"
+				eqawarn "           may exhibit random runtime failures."
+				eqawarn "${f}"
+				__vecho -ne '\n'
 			fi
-		done
+		fi
+
 		local cat_cmd=cat
 		[[ $PORTAGE_LOG_FILE = *.gz ]] && cat_cmd=zcat
 		[[ $reset_debug = 1 ]] && set -x