diff --git a/src/Model/Results/Results.py b/src/Model/Results/Results.py
index 0e0ce377..3b352bec 100644
--- a/src/Model/Results/Results.py
+++ b/src/Model/Results/Results.py
@@ -193,18 +193,19 @@ class Results(SQLSubModel):
             f"AND solver_type = '{solver_type}'"
         )
         if len(old_pid) != 0:
-            old_pid = old_pid[0]
+            for pid in old_pid:
+                pid = pid[0]
 
-            execute(
-                "DELETE FROM results " +
-                f"WHERE scenario = {self._owner_scenario} " +
-                f"AND solver_type = '{solver_type}'"
-            )
-            execute(
-                "DELETE FROM results_data " +
-                f"WHERE scenario = {self._owner_scenario} " +
-                f"AND results = '{old_pid}'"
-            )
+                execute(
+                    "DELETE FROM results " +
+                    f"WHERE scenario = {self._owner_scenario} " +
+                    f"AND solver_type = '{solver_type}'"
+                )
+                execute(
+                    "DELETE FROM results_data " +
+                    f"WHERE scenario = {self._owner_scenario} " +
+                    f"AND result = {pid}"
+                )
 
     def _db_save(self, execute, data=None):
         if self._status.scenario.id != self._owner_scenario: