diff --git a/src/zcash/IncrementalMerkleTree.cpp b/src/zcash/IncrementalMerkleTree.cpp
index 426abe1de..58f6a0bdc 100644
--- a/src/zcash/IncrementalMerkleTree.cpp
+++ b/src/zcash/IncrementalMerkleTree.cpp
@@ -59,12 +59,12 @@ void IncrementalMerkleTree<Depth, Hash>::wfcheck() const {
 
     // Left cannot be empty when right exists.
     if (!left && right) {
-        throw std::ios_base::failure("tree has non-canonical representation of tree");
+        throw std::ios_base::failure("tree has non-canonical representation; right should not exist");
     }
 
     // Left cannot be empty when parents is nonempty.
     if (!left && parents.size() > 0) {
-        throw std::ios_base::failure("tree has non-canonical representation of tree");
+        throw std::ios_base::failure("tree has non-canonical representation; parents should not be unempty");
     }
 }