diff --git a/did-resolver/src/lib.rs b/did-resolver/src/lib.rs
index 5edf2aff..e53390cc 100644
--- a/did-resolver/src/lib.rs
+++ b/did-resolver/src/lib.rs
@@ -1,6 +1,7 @@
 use error::Error;
 use hickory_resolver::proto::serialize::binary::BinEncodable;
 use hickory_resolver::TokioAsyncResolver;
+use reqwest::header::CONTENT_TYPE;
 use reqwest::{Client, StatusCode};
 
 pub mod error;
@@ -129,7 +130,16 @@ impl Resolver {
             .await?
             .error_for_status()?;
 
+        if let Some(ct) = res.headers().get(CONTENT_TYPE) {
+            if ct != "text/plain" {
+                return Ok(None);
+            }
+        }
+
         let did = res.text().await?;
+        if !did.starts_with("did:") {
+            return Ok(None);
+        }
 
         Ok(Some(did))
     }