diff --git a/fuzz/fuzz_targets/msg_targets/gen_target.sh b/fuzz/fuzz_targets/msg_targets/gen_target.sh
index 8e9ed04da..a74319f4f 100755
--- a/fuzz/fuzz_targets/msg_targets/gen_target.sh
+++ b/fuzz/fuzz_targets/msg_targets/gen_target.sh
@@ -1,5 +1,5 @@
 for target in CommitmentSigned FundingCreated FundingLocked FundingSigned OpenChannel RevokeAndACK Shutdown UpdateAddHTLC UpdateFailHTLC UpdateFailMalformedHTLC UpdateFee UpdateFulfillHTLC AcceptChannel ClosingSigned; do
-	tn=$(echo $target | sed 's/\([a-z0-9]\)\([A-Z]\)/\1_\L\2/g')
+	tn=$(echo $target | sed 's/\([a-z0-9]\)\([A-Z]\)/\1_\2/g')
 	fn=msg_$(echo $tn | tr '[:upper:]' '[:lower:]')_target.rs
 	cat msg_target_template.txt | sed s/MSG_TARGET/$target/ > $fn
 done