diff --git a/GeminiFormat/GeminiParser.swift b/GeminiFormat/GeminiParser.swift
index 41167e4..df169ed 100644
--- a/GeminiFormat/GeminiParser.swift
+++ b/GeminiFormat/GeminiParser.swift
@@ -39,7 +39,11 @@ public struct GeminiParser {
                 let urlEnd = line.firstWhitespaceIndex(after: urlStart)
                 let textStart = line.firstNonWhitespaceIndex(after: urlEnd)
                 
-                let urlString = String(line[urlStart..<urlEnd])
+                var urlString = String(line[urlStart..<urlEnd])
+                if urlString.hasPrefix("//") {
+                    // URL(string:relativeTo:) does not handle // meaning the same protocol as the base URL
+                    urlString = baseURL.scheme! + ":" + urlString
+                }
                 // todo: if the URL initializer fails, should there be a .link line with a nil URL?
                 let url = URL(string: urlString, relativeTo: baseURL)!.absoluteURL