diff --git a/t/lib/HydraTestContext.pm b/t/lib/HydraTestContext.pm
index 38a26ef6..43806c6f 100644
--- a/t/lib/HydraTestContext.pm
+++ b/t/lib/HydraTestContext.pm
@@ -189,7 +189,7 @@ sub write_file {
 }
 
 sub rand_chars {
-    return sprintf("%08X", rand(0xFFFFFFFF));
+    return sprintf("t%08X", rand(0xFFFFFFFF));
 }
 
 1;