diff --git a/src/fetch/mod.rs b/src/fetch/mod.rs
index 67165a9..f078cf6 100644
--- a/src/fetch/mod.rs
+++ b/src/fetch/mod.rs
@@ -65,9 +65,9 @@ pub async fn fetch_object_http<T: Clone, Kind: DeserializeOwned>(
     let content_type = res
         .content_type
         .as_ref()
-        .and_then(|c| c.to_str().ok())
+        .and_then(|c| Some(c.to_str().ok()?.to_lowercase()))
         .ok_or(Error::FetchInvalidContentType(res.url.clone()))?;
-    if !VALID_RESPONSE_CONTENT_TYPES.contains(&content_type) {
+    if !VALID_RESPONSE_CONTENT_TYPES.contains(&content_type.as_str()) {
         return Err(Error::FetchInvalidContentType(res.url));
     }