diff --git a/lib/camo/image.ex b/lib/camo/image.ex
index 5f1bf5a7..5c021970 100644
--- a/lib/camo/image.ex
+++ b/lib/camo/image.ex
@@ -1,20 +1,28 @@
 defmodule Camo.Image do
   def image_url(input) do
-    %{host: host} = URI.parse(input)
+    uri = URI.parse(input)
 
-    if !host or String.ends_with?(host, cdn_host()) or is_nil(camo_key()) do
-      input
-    else
-      camo_digest = :crypto.hmac(:sha, camo_key(), input) |> Base.encode16(case: :lower)
+    cond do
+      is_nil(uri.host) ->
+        ""
 
-      camo_uri = %URI{
-        host: camo_host(),
-        path: "/" <> camo_digest,
-        query: URI.encode_query(url: input),
-        scheme: "https"
-      }
+      is_nil(camo_key()) ->
+        input
 
-      URI.to_string(camo_uri)
+      uri.host in [cdn_host(), camo_host()] ->
+        URI.to_string(update_in(uri.scheme, fn _ -> "https" end))
+
+      true ->
+        camo_digest = :crypto.hmac(:sha, camo_key(), input) |> Base.encode16(case: :lower)
+
+        camo_uri = %URI{
+          host: camo_host(),
+          path: "/" <> camo_digest,
+          query: URI.encode_query(url: input),
+          scheme: "https"
+        }
+
+        URI.to_string(camo_uri)
     end
   end