diff --git a/tonic-web/src/call.rs b/tonic-web/src/call.rs
index 353e644e5..b9fd628a5 100644
--- a/tonic-web/src/call.rs
+++ b/tonic-web/src/call.rs
@@ -245,36 +245,41 @@ where
             let mut me = self.as_mut();
 
             loop {
-                let buf = ready!(me.as_mut().poll_decode(cx));
-
-                return if let Some(Ok(incoming_buf)) = buf {
-                    let buf = &mut me.as_mut().project().buf;
-
-                    buf.put(incoming_buf);
-
-                    match find_trailers(&buf[..]) {
-                        FindTrailers::Trailer(len) => {
-                            // Extract up to len of where the trailers are at
-                            let msg_buf = buf.copy_to_bytes(len);
-                            match decode_trailers_frame(buf.split().freeze()) {
-                                Ok(Some(trailers)) => {
-                                    self.project().trailers.replace(trailers);
-                                }
-                                Err(e) => return Poll::Ready(Some(Err(e))),
-                                _ => {}
-                            }
+                let incoming_buf = match ready!(me.as_mut().poll_decode(cx)) {
+                    Some(Ok(incoming_buf)) => incoming_buf,
+                    None => {
+                        // TODO: Consider eofing here?
+                        // Even if the buffer has more data, this will hit the eof branch
+                        // of decode in tonic
+                        return Poll::Ready(None);
+                    }
+                    Some(Err(e)) => return Poll::Ready(Some(Err(e))),
+                };
+
+                let buf = &mut me.as_mut().project().buf;
 
-                            if msg_buf.has_remaining() {
-                                return Poll::Ready(Some(Ok(msg_buf)));
-                            } else {
-                                return Poll::Ready(None);
+                buf.put(incoming_buf);
+
+                return match find_trailers(&buf[..])? {
+                    FindTrailers::Trailer(len) => {
+                        // Extract up to len of where the trailers are at
+                        let msg_buf = buf.copy_to_bytes(len);
+                        match decode_trailers_frame(buf.split().freeze()) {
+                            Ok(Some(trailers)) => {
+                                self.project().trailers.replace(trailers);
                             }
+                            Err(e) => return Poll::Ready(Some(Err(e))),
+                            _ => {}
+                        }
+
+                        if msg_buf.has_remaining() {
+                            Poll::Ready(Some(Ok(msg_buf)))
+                        } else {
+                            Poll::Ready(None)
                         }
-                        FindTrailers::IncompleteBuf => continue,
-                        FindTrailers::Done => Poll::Ready(Some(Ok(buf.split().freeze()))),
                     }
-                } else {
-                    Poll::Ready(buf)
+                    FindTrailers::IncompleteBuf => continue,
+                    FindTrailers::Done(len) => Poll::Ready(Some(Ok(buf.split_to(len).freeze()))),
                 };
             }
         }
@@ -421,7 +426,7 @@ fn make_trailers_frame(trailers: HeaderMap) -> Vec<u8> {
 /// its location in the original buf. If `None` is returned we did
 /// not find a trailers in this buffer either because its incomplete
 /// or the buffer jsut contained grpc message frames.
-fn find_trailers(buf: &[u8]) -> FindTrailers {
+fn find_trailers(buf: &[u8]) -> Result<FindTrailers, Status> {
     let mut len = 0;
     let mut temp_buf = &buf[..];
 
@@ -429,13 +434,17 @@ fn find_trailers(buf: &[u8]) -> FindTrailers {
         // To check each frame, there must be at least GRPC_HEADER_SIZE
         // amount of bytes available otherwise the buffer is incomplete.
         if temp_buf.is_empty() || temp_buf.len() < GRPC_HEADER_SIZE {
-            return FindTrailers::Done;
+            return Ok(FindTrailers::Done(len));
         }
 
         let header = temp_buf.get_u8();
 
         if header == GRPC_WEB_TRAILERS_BIT {
-            return FindTrailers::Trailer(len);
+            return Ok(FindTrailers::Trailer(len));
+        }
+
+        if !(header == 0 || header == 1) {
+            return Err(Status::internal("Invalid header bit {} expected 0 or 1"));
         }
 
         let msg_len = temp_buf.get_u32();
@@ -445,7 +454,7 @@ fn find_trailers(buf: &[u8]) -> FindTrailers {
         // If the msg len of a non-grpc-web trailer frame is larger than
         // the overall buffer we know within that buffer there are no trailers.
         if len > buf.len() {
-            return FindTrailers::IncompleteBuf;
+            return Ok(FindTrailers::IncompleteBuf);
         }
 
         temp_buf = &buf[len as usize..];
@@ -456,11 +465,13 @@ fn find_trailers(buf: &[u8]) -> FindTrailers {
 enum FindTrailers {
     Trailer(usize),
     IncompleteBuf,
-    Done,
+    Done(usize),
 }
 
 #[cfg(test)]
 mod tests {
+    use tonic::Code;
+
     use super::*;
 
     #[test]
@@ -507,7 +518,7 @@ mod tests {
             128, 0, 0, 0, 15, 103, 114, 112, 99, 45, 115, 116, 97, 116, 117, 115, 58, 48, 13, 10,
         ];
 
-        let out = find_trailers(&buf[..]);
+        let out = find_trailers(&buf[..]).unwrap();
 
         assert_eq!(out, FindTrailers::Trailer(0));
     }
@@ -524,7 +535,7 @@ mod tests {
             15, 103, 114, 112, 99, 45, 115, 116, 97, 116, 117, 115, 58, 48, 13, 10,
         ];
 
-        let out = find_trailers(&buf[..]);
+        let out = find_trailers(&buf[..]).unwrap();
 
         assert_eq!(out, FindTrailers::Trailer(81));
 
@@ -566,8 +577,17 @@ mod tests {
             105, 116, 116, 101, 110, 32, 98, 121, 32,
         ];
 
-        let out = find_trailers(&buf[..]);
+        let out = find_trailers(&buf[..]).unwrap();
 
         assert_eq!(out, FindTrailers::IncompleteBuf);
     }
+
+    #[test]
+    #[ignore]
+    fn find_trailers_buffered_incomplete_buf_bug() {
+        let buf = std::fs::read("tests/incomplete-buf-bug.bin").unwrap();
+        let out = find_trailers(&buf[..]).unwrap_err();
+
+        assert_eq!(out.code(), Code::Internal);
+    }
 }
diff --git a/tonic-web/tests/incomplete-buf-bug.bin b/tonic-web/tests/incomplete-buf-bug.bin
new file mode 100644
index 000000000..19cb7417b
Binary files /dev/null and b/tonic-web/tests/incomplete-buf-bug.bin differ
diff --git a/tonic/src/codec/decode.rs b/tonic/src/codec/decode.rs
index 4c1068271..38644b6e5 100644
--- a/tonic/src/codec/decode.rs
+++ b/tonic/src/codec/decode.rs
@@ -253,7 +253,7 @@ impl StreamingInner {
         } else {
             // FIXME: improve buf usage.
             if self.buf.has_remaining() {
-                trace!("unexpected EOF decoding stream");
+                trace!("unexpected EOF decoding stream, state: {:?}", self.state);
                 Err(Status::new(
                     Code::Internal,
                     "Unexpected EOF decoding stream.".to_string(),