diff --git a/pipeline/02_warc_parse/warc.go b/pipeline/02_warc_parse/warc.go
index 7ae4645..246e741 100644
--- a/pipeline/02_warc_parse/warc.go
+++ b/pipeline/02_warc_parse/warc.go
@@ -117,9 +117,11 @@ func CheckIframeAllowed(headers http.Header) bool {
 		return false
 	}
 
-	csp := strings.ToLower(headers.Get("Content-Security-Policy"))
-	if strings.Contains(csp, "frame-ancestors") && !strings.Contains(csp, "frame-ancestors *") {
-		return false
+	for _, csp := range headers.Values("Content-Security-Policy") {
+		csp = strings.ToLower(csp)
+		if strings.Contains(csp, "frame-ancestors") && !strings.Contains(csp, "frame-ancestors *") {
+			return false
+		}
 	}
 
 	return true