diff --git a/librustzcash-wrapper/src/lib.rs b/librustzcash-wrapper/src/lib.rs
index df054c6..1673061 100644
--- a/librustzcash-wrapper/src/lib.rs
+++ b/librustzcash-wrapper/src/lib.rs
@@ -1590,7 +1590,7 @@ pub extern "C" fn rust_wrapper_combine_orchard_nodes(
     ){
     let left_in: Vec<u8> = marshall_from_haskell_var(left, left_len, RW);
     let right_in: Vec<u8> = marshall_from_haskell_var(right, right_len, RW);
-    if left_in.len() > 1 {
+    if left_in.len() == 1 {
             let n = MerkleHashOrchard::combine(Level::new(level), &MerkleHashOrchard::empty_leaf(), &MerkleHashOrchard::empty_leaf());
             let h = Hhex { bytes: n.to_bytes().to_vec() };
             marshall_to_haskell_var(&h, out, out_len, RW);