diff --git a/tower-http/CHANGELOG.md b/tower-http/CHANGELOG.md
index 020c0d06..5ac55120 100644
--- a/tower-http/CHANGELOG.md
+++ b/tower-http/CHANGELOG.md
@@ -21,7 +21,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Fixed
 
-- None.
+- **trace:** Correctly identify gRPC requests in default `on_response` callback ([#278])
+
+[#278]: https://github.com/tower-rs/tower-http/pull/278
 
 # 0.3.4 (June 06, 2022)
 
diff --git a/tower-http/src/trace/on_response.rs b/tower-http/src/trace/on_response.rs
index 09f44e58..573de2e4 100644
--- a/tower-http/src/trace/on_response.rs
+++ b/tower-http/src/trace/on_response.rs
@@ -264,10 +264,23 @@ impl<B> OnResponse<B> for DefaultOnResponse {
 fn status<B>(res: &Response<B>) -> Option<i32> {
     use crate::classify::grpc_errors_as_failures::ParsedGrpcStatus;
 
+    // gRPC-over-HTTP2 uses the "application/grpc[+format]" content type, and gRPC-Web uses
+    // "application/grpc-web[+format]" or "application/grpc-web-text[+format]", where "format" is
+    // the message format, e.g. +proto, +json.
+    //
+    // So, valid grpc content types include (but are not limited to):
+    //  - application/grpc
+    //  - application/grpc+proto
+    //  - application/grpc-web+proto
+    //  - application/grpc-web-text+proto
+    //
+    // For simplicity, we simply check that the content type starts with "application/grpc".
     let is_grpc = res
         .headers()
         .get(http::header::CONTENT_TYPE)
-        .map_or(false, |value| value == "application/grpc");
+        .map_or(false, |value| {
+            value.as_bytes().starts_with("application/grpc".as_bytes())
+        });
 
     if is_grpc {
         match crate::classify::grpc_errors_as_failures::classify_grpc_metadata(