diff --git a/src/DIRAC/WorkloadManagementSystem/DB/PilotAgentsDB.py b/src/DIRAC/WorkloadManagementSystem/DB/PilotAgentsDB.py
index 1a791ea54ef..69ab50f6c90 100755
--- a/src/DIRAC/WorkloadManagementSystem/DB/PilotAgentsDB.py
+++ b/src/DIRAC/WorkloadManagementSystem/DB/PilotAgentsDB.py
@@ -194,19 +194,13 @@ def deletePilots(self, pilotIDs, conn=False):
         if not isinstance(pilotIDs, list):
             return S_ERROR("Input argument is not a List")
 
-        failed = []
-
         result = self._escapeValues(pilotIDs)
         if not result["OK"]:
             return S_ERROR(f"Failed to remove pilot: {result['Value']}")
         stringIDs = ",".join(result["Value"])
-        for table in ["PilotOutput", "JobToPilotMapping", "PilotAgents"]:
-            result = self._update(f"DELETE FROM {table} WHERE PilotID in ({stringIDs})", conn=conn)
-            if not result["OK"]:
-                failed.append(table)
-
-        if failed:
-            return S_ERROR(f"Failed to remove pilot from {', '.join(failed)} tables")
+        result = self._update(f"DELETE FROM PilotAgents WHERE PilotID in ({stringIDs})", conn=conn)
+        if not result["OK"]:
+            return S_ERROR("Failed to remove pilots: ", result["Message"])
         return S_OK(pilotIDs)
 
     ##########################################################################################
diff --git a/src/DIRAC/WorkloadManagementSystem/DB/PilotAgentsDB.sql b/src/DIRAC/WorkloadManagementSystem/DB/PilotAgentsDB.sql
index 24cbe5a82b8..8b6f8eb6a10 100755
--- a/src/DIRAC/WorkloadManagementSystem/DB/PilotAgentsDB.sql
+++ b/src/DIRAC/WorkloadManagementSystem/DB/PilotAgentsDB.sql
@@ -55,8 +55,8 @@ CREATE TABLE `JobToPilotMapping` (
   `PilotID` INT(11) UNSIGNED NOT NULL,
   `JobID` INT(11) UNSIGNED NOT NULL,
   `StartTime` DATETIME NOT NULL,
-  KEY `JobID` (`JobID`),
-  KEY `PilotID` (`PilotID`)
+  PRIMARY KEY (`PilotID`, `JobID`),
+  FOREIGN KEY (`PilotID`) REFERENCES `PilotAgents`(`PilotID`) ON DELETE CASCADE
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
 
 DROP TABLE IF EXISTS `PilotOutput`;
@@ -64,5 +64,6 @@ CREATE TABLE `PilotOutput` (
   `PilotID` INT(11) UNSIGNED NOT NULL,
   `StdOutput` MEDIUMTEXT,
   `StdError` MEDIUMTEXT,
-  PRIMARY KEY (`PilotID`)
+  PRIMARY KEY (`PilotID`),
+  FOREIGN KEY (`PilotID`) REFERENCES `PilotAgents`(`PilotID`) ON DELETE CASCADE
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;