diff --git a/reg-tests/cache/caching_rules.vtc b/reg-tests/cache/caching_rules.vtc
index c20a720..114b2fd 100644
--- a/reg-tests/cache/caching_rules.vtc
+++ b/reg-tests/cache/caching_rules.vtc
@@ -78,6 +78,12 @@
 } -start
 
 haproxy h1 -conf {
+    global
+        # WT: limit false-positives causing "HTTP header incomplete" due to
+        # idle server connections being randomly used and randomly expiring
+        # under us.
+        tune.idle-pool.shared off
+
     defaults
         mode http
         ${no-htx} option http-use-htx