diff --git a/src/DIRAC/TransformationSystem/Client/TransformationClient.py b/src/DIRAC/TransformationSystem/Client/TransformationClient.py
index e442ce65ce1..25d2266be71 100644
--- a/src/DIRAC/TransformationSystem/Client/TransformationClient.py
+++ b/src/DIRAC/TransformationSystem/Client/TransformationClient.py
@@ -180,7 +180,9 @@ def getTransformationFiles(
             res = rpcClient.getTransformationFilesAsJsonString(
                 condDict, older, newer, timeStamp, orderAttribute, offset, maxfiles, columns
             )
-            res, _ = jdecode(res)
+            if not res["OK"]:
+                return res
+            res, _ = jdecode(res["Value"])
             # TransformationDB.getTransformationFiles includes a "Records"/"ParameterNames"
             # that we don't want to return to the client so explicitly return S_OK with the value
             if not res["OK"]:
@@ -209,7 +211,9 @@ def getTransformationFiles(
             res = rpcClient.getTransformationFilesAsJsonString(
                 condDict, older, newer, timeStamp, orderAttribute, None, None, columns
             )
-            res, _ = jdecode(res)
+            if not res["OK"]:
+                return res
+            res, _ = jdecode(res["Value"])
             if not res["OK"]:
                 gLogger.error(
                     "Error getting files for transformation %s (offset %d), %s"