diff --git a/coordinator/tributary/src/blockchain.rs b/coordinator/tributary/src/blockchain.rs
index 86b7f37b..f73c874b 100644
--- a/coordinator/tributary/src/blockchain.rs
+++ b/coordinator/tributary/src/blockchain.rs
@@ -54,16 +54,23 @@ impl<T: Transaction> Blockchain<T> {
     block.verify(self.genesis, self.tip, locally_provided, self.next_nonces.clone())
   }
 
-  /// Add a block, assuming it's valid.
-  ///
-  /// Do not call this without either verifying the block or having it confirmed under consensus.
-  /// Doing so will cause a panic or action an invalid transaction.
-  pub fn add_block(&mut self, block: &Block<T>) {
+  /// Add a block.
+  #[must_use]
+  pub fn add_block(&mut self, block: &Block<T>) -> bool {
+    // TODO: Handle desyncs re: provided transactions properly
+    if self.verify_block(block).is_err() {
+      return false;
+    }
+
+    // None of the following assertions should be reachable since we verified the block
     self.tip = block.hash();
     for tx in &block.transactions {
       match tx.kind() {
         TransactionKind::Provided => {
-          self.provided.withdraw(tx.hash());
+          assert!(
+            self.provided.withdraw(tx.hash()),
+            "verified block had a provided transaction we didn't have"
+          );
         }
         TransactionKind::Unsigned => {}
         TransactionKind::Signed(Signed { signer, nonce, .. }) => {
@@ -72,10 +79,12 @@ impl<T: Transaction> Blockchain<T> {
             .insert(*signer, nonce + 1)
             .expect("block had signed transaction from non-participant");
           if prev != *nonce {
-            panic!("block had an invalid nonce");
+            panic!("verified block had an invalid nonce");
           }
         }
       }
     }
+
+    true
   }
 }
diff --git a/coordinator/tributary/src/tests/blockchain.rs b/coordinator/tributary/src/tests/blockchain.rs
index 4ccd793a..c4c49f43 100644
--- a/coordinator/tributary/src/tests/blockchain.rs
+++ b/coordinator/tributary/src/tests/blockchain.rs
@@ -35,7 +35,7 @@ fn block_addition() {
   assert_eq!(block.header.parent, genesis);
   assert_eq!(block.header.transactions, [0; 32]);
   blockchain.verify_block(&block).unwrap();
-  blockchain.add_block(&block);
+  assert!(blockchain.add_block(&block));
   assert_eq!(blockchain.tip(), block.hash());
 }
 
@@ -155,7 +155,7 @@ fn signed_transaction() {
 
     // Verify and add the block
     blockchain.verify_block(&block).unwrap();
-    blockchain.add_block(&block);
+    assert!(blockchain.add_block(&block));
     assert_eq!(blockchain.tip(), block.hash());
   };
 
@@ -194,11 +194,11 @@ fn provided_transaction() {
   blockchain.verify_block(&block).unwrap();
 
   // add_block should work for verified blocks
-  blockchain.add_block(&block);
+  assert!(blockchain.add_block(&block));
 
   let block = Block::new(blockchain.tip(), &txs, HashMap::new());
   // The provided transaction should no longer considered provided, causing this error
   assert!(blockchain.verify_block(&block).is_err());
-  // add_block should also work for unverified provided transactions if told to add them
-  blockchain.add_block(&block);
+  // add_block should fail for unverified provided transactions if told to add them
+  assert!(!blockchain.add_block(&block));
 }
diff --git a/coordinator/tributary/src/transaction.rs b/coordinator/tributary/src/transaction.rs
index 290038d0..d4e9aa0e 100644
--- a/coordinator/tributary/src/transaction.rs
+++ b/coordinator/tributary/src/transaction.rs
@@ -58,8 +58,6 @@ impl ReadWrite for Signed {
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub enum TransactionKind<'a> {
   /// This tranaction should be provided by every validator, solely ordered by the block producer.
-  ///
-  /// This transaction is only valid if a supermajority of validators provided it.
   Provided,
 
   /// An unsigned transaction, only able to be included by the block producer.