diff --git a/src/ai_marketplace_monitor/facebook.py b/src/ai_marketplace_monitor/facebook.py
index 55c8859..122d6d0 100644
--- a/src/ai_marketplace_monitor/facebook.py
+++ b/src/ai_marketplace_monitor/facebook.py
@@ -280,7 +280,7 @@ def search(
                     if not self.filter_item(item, item_config):
                         continue
                     try:
-                        details = self.get_item_details(item.post_url)
+                        details = self.get_item_details(f"https://www.facebook.com{item.post_url}")
                         time.sleep(5)
                     except Exception as e:
                         self.logger.error(f"Error getting item details: {e}")
@@ -305,7 +305,7 @@ def get_item_details(self: "FacebookMarketplace", post_url: str) -> SearchedItem
             self.login()
 
         assert self.page is not None
-        self.goto_url(f"https://www.facebook.com{post_url}")
+        self.goto_url(post_url)
         details = FacebookItemPage(self.page.content(), self.logger).parse(post_url)
         cache.set((CacheType.ITEM_DETAILS.value, post_url), details, tag="item_details")
         return details
diff --git a/src/ai_marketplace_monitor/monitor.py b/src/ai_marketplace_monitor/monitor.py
index 77452de..5c044df 100644
--- a/src/ai_marketplace_monitor/monitor.py
+++ b/src/ai_marketplace_monitor/monitor.py
@@ -243,11 +243,11 @@ def check_items(
             for post_url in post_urls or []:
                 if "?" in post_url:
                     post_url = post_url.split("?")[0]
-                if post_url.startswith("https://www.facebook.com"):
-                    post_url = post_url[len("https://www.facebook.com") :]
                 if post_url.isnumeric():
-                    post_url = f"/marketplace/item/{post_url}/"
+                    post_url = f"https://www.facebook.com/marketplace/item/{post_url}/"
 
+                if not post_url.startswith("https://www.facebook.com/marketplace/item"):
+                    raise ValueError(f"URL {post_url} is not a valid Facebook Marketplace URL.")
                 # check if item in config
                 assert self.config is not None