diff --git a/src/lib.rs b/src/lib.rs
index dfe8d55..600f959 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -61,6 +61,7 @@ pub fn time_to_blockheight(time: DateTime<Utc>, bi: BlockchainInfo) -> BlockHeig
 #[cfg(test)]
 mod tests {
     use super::*;
+    use chrono::Duration;
 
     #[test]
     fn one_block_time_away() {
@@ -100,4 +101,30 @@ mod tests {
         let result = time_to_blockheight(wanted_negative_block_time, blockchain_info);
         assert_eq!(result, -1);
     }
+
+    #[test]
+    fn a_next_block_on_some_blockchains() {
+        // Doesn't feel like an overly good test - but I can't think of anyother way that's "dynamic"
+        // to me manually updating the times above
+        let bi: BlockchainInfo = BlockchainSupported::BTC.into();
+        let wanted_time = bi.latest_block_time + Duration::seconds(bi.block_period as i64 + 1);
+        let bh = time_to_blockheight_specific_chain(wanted_time, BlockchainSupported::BTC);
+        assert_eq!(bh, bi.latest_block_height + 1);
+        let bi: BlockchainInfo = BlockchainSupported::BSV.into();
+        let wanted_time = bi.latest_block_time + Duration::seconds(bi.block_period as i64 + 2);
+        let bh = time_to_blockheight_specific_chain(wanted_time, BlockchainSupported::BSV);
+        assert_eq!(bh, bi.latest_block_height + 1);
+        let bi: BlockchainInfo = BlockchainSupported::XMR.into();
+        let wanted_time = bi.latest_block_time + Duration::seconds(bi.block_period as i64 + 3);
+        let bh = time_to_blockheight_specific_chain(wanted_time, BlockchainSupported::XMR);
+        assert_eq!(bh, bi.latest_block_height + 1);
+        let bi: BlockchainInfo = BlockchainSupported::ETH.into();
+        let wanted_time = bi.latest_block_time + Duration::seconds(bi.block_period as i64 + 4);
+        let bh = time_to_blockheight_specific_chain(wanted_time, BlockchainSupported::ETH);
+        assert_eq!(bh, bi.latest_block_height + 1);
+        let bi: BlockchainInfo = BlockchainSupported::ETH.into();
+        let wanted_time = bi.latest_block_time + Duration::seconds(bi.block_period as i64 + 5);
+        let bh = time_to_blockheight_specific_chain(wanted_time, BlockchainSupported::XMR);
+        assert_ne!(bh, bi.latest_block_height + 1);
+    }
 }