diff --git a/modules/dcache-bulk/src/main/java/org/dcache/services/bulk/activity/plugin/pin/StageActivity.java b/modules/dcache-bulk/src/main/java/org/dcache/services/bulk/activity/plugin/pin/StageActivity.java
index d915ec463c1..8db0f538ae9 100644
--- a/modules/dcache-bulk/src/main/java/org/dcache/services/bulk/activity/plugin/pin/StageActivity.java
+++ b/modules/dcache-bulk/src/main/java/org/dcache/services/bulk/activity/plugin/pin/StageActivity.java
@@ -180,7 +180,7 @@ private void checkStageable(FileAttributes attributes) throws CacheException {
         checkPinnable(attributes);
 
         if (attributes.getRetentionPolicy() != RetentionPolicy.CUSTODIAL) {
-            throw new CacheException(INVALID_ARGS, "File not on tape.");
+            throw new CacheException(INVALID_ARGS, "Cannot stage DISK only files");
         }
     }