diff --git a/zebrad/src/commands/start/sync.rs b/zebrad/src/commands/start/sync.rs
index 866fcafd..6f0413f9 100644
--- a/zebrad/src/commands/start/sync.rs
+++ b/zebrad/src/commands/start/sync.rs
@@ -226,8 +226,13 @@ where
                         continue;
                     };
 
+                    // Make sure we get the same tips, regardless of the
+                    // order of peer responses
                     if !download_set.contains(&new_tip.expected_next) {
-                        tracing::debug!(?new_tip, "adding new prospective tip");
+                        tracing::debug!(?new_tip,
+                                        "adding new prospective tip, and removing existing tips in the new block hash list");
+                        self.prospective_tips
+                            .retain(|t| !unknown_hashes.contains(&t.expected_next));
                         self.prospective_tips.insert(new_tip);
                     } else {
                         tracing::debug!(?new_tip, "discarding tip already queued for download");
@@ -305,8 +310,13 @@ where
 
                         tracing::trace!(?hashes);
 
+                        // Make sure we get the same tips, regardless of the
+                        // order of peer responses
                         if !download_set.contains(&new_tip.expected_next) {
-                            tracing::debug!(?new_tip, "adding new prospective tip");
+                            tracing::debug!(?new_tip,
+                                            "adding new prospective tip, and removing any existing tips in the new block hash list");
+                            self.prospective_tips
+                                .retain(|t| !unknown_hashes.contains(&t.expected_next));
                             self.prospective_tips.insert(new_tip);
                         } else {
                             tracing::debug!(?new_tip, "discarding tip already queued for download");