diff --git a/ci/pin-msrv.sh b/ci/pin-msrv.sh
index 72658e55..37ff97d1 100755
--- a/ci/pin-msrv.sh
+++ b/ci/pin-msrv.sh
@@ -11,3 +11,4 @@ set -euo pipefail
 # rustup override set 1.63.0
 
 cargo update -p once_cell --precise "1.20.3"
+cargo update -p syn --precise "2.0.106"