diff --git a/cmd/web.go b/cmd/web.go
index f2e21a9..0f2bd06 100644
--- a/cmd/web.go
+++ b/cmd/web.go
@@ -203,23 +203,23 @@ func extractAndConvertContent(urlStr string) (string, error) {
 	return header + markdown + "\n\n", nil
 }
 
-func getFilenameFromContent(content, urlStr string) string {
+func getFilenameFromContent(content, urlStr string) (string, error) {
 	// Try to extract title from content
 	titleStart := strings.Index(content, "<title>")
 	titleEnd := strings.Index(content, "</title>")
 	if titleStart != -1 && titleEnd != -1 && titleEnd > titleStart {
 		title := content[titleStart+7 : titleEnd]
-		return sanitizeFilename(title) + ".md"
+		return sanitizeFilename(title) + ".rollup.md", nil
 	}
 
 	// If no title found, use the URL without the protocol
 	parsedURL, err := url.Parse(urlStr)
 	if err != nil {
-		return "untitled.md"
+		return "", fmt.Errorf("invalid URL: %v", err)
 	}
 	
 	filename := parsedURL.Host + parsedURL.Path
-	return sanitizeFilename(filename) + ".md"
+	return sanitizeFilename(filename) + ".rollup.md", nil
 }
 
 func sanitizeFilename(name string) string {
diff --git a/cmd/web_test.go b/cmd/web_test.go
index a452525..739f320 100644
--- a/cmd/web_test.go
+++ b/cmd/web_test.go
@@ -70,18 +70,28 @@ func TestGetFilenameFromContent(t *testing.T) {
 		content  string
 		url      string
 		expected string
+		expectErr bool
 	}{
-		{"<title>Test Page</title>", "http://example.com", "Test_Page.md"},
-		{"No title here", "http://example.com/page", "example_com_page.md"},
-		{"<title>  Trim  Me  </title>", "http://example.com", "Trim_Me.md"},
-		{"<title></title>", "http://example.com", "example_com.md"},
-		{"Invalid URL", "not a valid url", "untitled.md"},
+		{"<title>Test Page</title>", "http://example.com", "Test_Page.rollup.md", false},
+		{"No title here", "http://example.com/page", "example_com_page.rollup.md", false},
+		{"<title>  Trim  Me  </title>", "http://example.com", "Trim_Me.rollup.md", false},
+		{"<title></title>", "http://example.com", "example_com.rollup.md", false},
+		{"Invalid URL", "not a valid url", "", true},
 	}
 
 	for _, test := range tests {
-		result := getFilenameFromContent(test.content, test.url)
-		if result != test.expected {
-			t.Errorf("getFilenameFromContent(%q, %q) = %q; want %q", test.content, test.url, result, test.expected)
+		result, err := getFilenameFromContent(test.content, test.url)
+		if test.expectErr {
+			if err == nil {
+				t.Errorf("getFilenameFromContent(%q, %q) expected an error, but got none", test.content, test.url)
+			}
+		} else {
+			if err != nil {
+				t.Errorf("getFilenameFromContent(%q, %q) unexpected error: %v", test.content, test.url, err)
+			}
+			if result != test.expected {
+				t.Errorf("getFilenameFromContent(%q, %q) = %q; want %q", test.content, test.url, result, test.expected)
+			}
 		}
 	}
 }