diff --git a/quinn-proto/src/connection.rs b/quinn-proto/src/connection.rs
index 69fe432e1..331e146a3 100644
--- a/quinn-proto/src/connection.rs
+++ b/quinn-proto/src/connection.rs
@@ -1440,23 +1440,7 @@ where
                                     self.reject_0rtt();
                                 } else {
                                     self.accepted_0rtt = true;
-                                    if params.initial_max_data < self.params.initial_max_data
-                                        || params.initial_max_stream_data_bidi_local
-                                            < self.params.initial_max_stream_data_bidi_local
-                                        || params.initial_max_stream_data_bidi_remote
-                                            < self.params.initial_max_stream_data_bidi_remote
-                                        || params.initial_max_stream_data_uni
-                                            < self.params.initial_max_stream_data_uni
-                                        || params.initial_max_streams_bidi
-                                            < self.params.initial_max_streams_bidi
-                                        || params.initial_max_streams_uni
-                                            < self.params.initial_max_streams_uni
-                                    {
-                                        return Err(TransportError::PROTOCOL_VIOLATION(
-                                            "flow control parameters were reduced wrt. 0-RTT",
-                                        )
-                                        .into());
-                                    }
+                                    params.validate_0rtt(&self.params)?;
                                 }
                             }
                             if let Some(token) = params.stateless_reset_token {
diff --git a/quinn-proto/src/transport_parameters.rs b/quinn-proto/src/transport_parameters.rs
index 0cabd4908..89fc7eac6 100644
--- a/quinn-proto/src/transport_parameters.rs
+++ b/quinn-proto/src/transport_parameters.rs
@@ -94,6 +94,24 @@ impl TransportParameters {
             ..Self::default()
         }
     }
+
+    /// Check that these parameters are legal when resuming from
+    /// certain cached parameters
+    pub fn validate_0rtt(&self, cached: &TransportParameters) -> Result<(), TransportError> {
+        if cached.initial_max_data < self.initial_max_data
+            || cached.initial_max_stream_data_bidi_local < self.initial_max_stream_data_bidi_local
+            || cached.initial_max_stream_data_bidi_remote < self.initial_max_stream_data_bidi_remote
+            || cached.initial_max_stream_data_uni < self.initial_max_stream_data_uni
+            || cached.initial_max_streams_bidi < self.initial_max_streams_bidi
+            || cached.initial_max_streams_uni < self.initial_max_streams_uni
+        {
+            return Err(TransportError::PROTOCOL_VIOLATION(
+                "0-RTT accepted with incompatible transport parameters",
+            )
+            .into());
+        }
+        Ok(())
+    }
 }
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]