diff --git a/paramspider/client.py b/paramspider/client.py
index 09db654..c617caf 100644
--- a/paramspider/client.py
+++ b/paramspider/client.py
@@ -64,4 +64,4 @@ def fetch_url_content(url,proxy):
             sys.exit()
 
     logging.error(f"Failed to fetch URL {url} after {MAX_RETRIES} retries.")
-    sys.exit()
+    return None
diff --git a/paramspider/main.py b/paramspider/main.py
index 38ff9f5..6e434fd 100644
--- a/paramspider/main.py
+++ b/paramspider/main.py
@@ -93,6 +93,8 @@ def fetch_and_clean_urls(domain, extensions, stream_output,proxy, placeholder):
     logging.info(f"{Fore.YELLOW}[INFO]{Style.RESET_ALL} Fetching URLs for {Fore.CYAN + domain + Style.RESET_ALL}")
     wayback_uri = f"https://web.archive.org/cdx/search/cdx?url={domain}/*&output=txt&collapse=urlkey&fl=original&page=/"
     response = client.fetch_url_content(wayback_uri,proxy)
+    if response == None:
+        return
     urls = response.text.split()
     
     logging.info(f"{Fore.YELLOW}[INFO]{Style.RESET_ALL} Found {Fore.GREEN + str(len(urls)) + Style.RESET_ALL} URLs for {Fore.CYAN + domain + Style.RESET_ALL}")
@@ -165,4 +167,4 @@ def main():
             fetch_and_clean_urls(domain, extensions, args.stream,args.proxy, args.placeholder)
 
 if __name__ == "__main__":
-    main()
\ No newline at end of file
+    main()