diff --git a/lib/services/entity-sync.ts b/lib/services/entity-sync.ts
index e4b9bbb..b791572 100644
--- a/lib/services/entity-sync.ts
+++ b/lib/services/entity-sync.ts
@@ -274,16 +274,17 @@ export class EntitySyncService {
         }
       }
 
-      // Validate project foreign keys for tasks
+      // Validate project and resource foreign keys for tasks
       if (entity === EntityType.TASKS) {
         const initialCount = mappedRecords.length;
         
-        // Get all valid project IDs from database
+        // Get all valid project IDs and resource IDs from database
         const validProjectIds = await this.getValidProjectIds();
+        const validResourceIds = await this.getValidResourceIds();
         
-        // Filter tasks with invalid project references
+        // Filter tasks with invalid foreign key references
         mappedRecords = mappedRecords.map(task => {
-          // Set invalid project IDs to null instead of filtering out the entire task
+          // Set invalid project IDs to null
           if (task.project_id && !validProjectIds.has(task.project_id)) {
             entityLogger.debug(`Invalid project_id, setting to null`, {
               taskId: task.id,
@@ -291,12 +292,35 @@ export class EntitySyncService {
             });
             task.project_id = null;
           }
+          
+          // Set invalid resource IDs to null
+          if (task.assigned_resource_id && !validResourceIds.has(task.assigned_resource_id)) {
+            entityLogger.debug(`Invalid assigned_resource_id, setting to null`, {
+              taskId: task.id,
+              invalidResourceId: task.assigned_resource_id,
+            });
+            task.assigned_resource_id = null;
+          }
+          if (task.creator_resource_id && !validResourceIds.has(task.creator_resource_id)) {
+            task.creator_resource_id = null;
+          }
+          if (task.completed_by_resource_id && !validResourceIds.has(task.completed_by_resource_id)) {
+            task.completed_by_resource_id = null;
+          }
+          if (task.last_activity_resource_id && !validResourceIds.has(task.last_activity_resource_id)) {
+            task.last_activity_resource_id = null;
+          }
+          
           return task;
         });
         
-        const nullifiedCount = initialCount - mappedRecords.filter(t => t.project_id).length;
-        if (nullifiedCount > 0) {
-          entityLogger.warn('Nullified invalid project references', { nullifiedCount });
+        const nullifiedProjectCount = initialCount - mappedRecords.filter(t => t.project_id).length;
+        const nullifiedResourceCount = initialCount - mappedRecords.filter(t => t.assigned_resource_id).length;
+        if (nullifiedProjectCount > 0 || nullifiedResourceCount > 0) {
+          entityLogger.warn('Nullified invalid foreign key references', { 
+            nullifiedProjectCount, 
+            nullifiedResourceCount 
+          });
         }
       }