diff --git a/install.sh b/install.sh
index f32403d966..11ff394ddc 100755
--- a/install.sh
+++ b/install.sh
@@ -126,9 +126,12 @@ echo_latest_mainline_version() {
 		exit 1
 	fi
 
+	# Filter to strict semver (MAJOR.MINOR.PATCH) to exclude
+	# pre-release tags like RC builds from version resolution.
 	echo "$body" |
 		awk -F'"' '/"tag_name"/ {print $4}' |
 		tr -d v |
+		grep '^[0-9]\+\.[0-9]\+\.[0-9]\+$' |
 		tr . ' ' |
 		sort -k1,1nr -k2,2nr -k3,3nr |
 		head -n1 |