diff --git a/contrib/test.sh b/contrib/test.sh
index 04031f7aa8..4275595190 100755
--- a/contrib/test.sh
+++ b/contrib/test.sh
@@ -24,6 +24,9 @@ fi
 
 # We should not have any duplicate dependencies. This catches mistakes made upgrading dependencies
 # in one crate and not in another (e.g. upgrade bitcoin_hashes in bitcoin but not in secp).
+cargo update -p serde --precise 1.0.142
+cargo update -p serde_test --precise 1.0.142
+cargo update -p serde_derive --precise 1.0.142
 duplicate_dependencies=$(cargo tree  --target=all --all-features --duplicates | wc -l)
 if [ "$duplicate_dependencies" -ne 0 ]; then
     echo "Dependency tree is broken, contains duplicates"