diff --git a/lightningd/chaintopology.c b/lightningd/chaintopology.c
index 0999f31f1..1c50688d4 100644
--- a/lightningd/chaintopology.c
+++ b/lightningd/chaintopology.c
@@ -468,6 +468,13 @@ static void get_init_blockhash(struct bitcoind *bitcoind, u32 blockcount,
 	if (blockcount < topo->first_blocknum)
 		topo->first_blocknum = blockcount;
 
+	/* FIXME: Because we don't handle our root disappearing, we go
+	 * 100 blocks back */
+	if (topo->first_blocknum < 100)
+		topo->first_blocknum = 0;
+	else
+		topo->first_blocknum -= 100;
+
 	/* Get up to speed with topology. */
 	bitcoind_getblockhash(bitcoind, topo->first_blocknum,
 			      get_init_block, topo);
diff --git a/tests/test_lightningd.py b/tests/test_lightningd.py
index 4c1bc2a10..a420b4385 100644
--- a/tests/test_lightningd.py
+++ b/tests/test_lightningd.py
@@ -224,6 +224,11 @@ class BaseLightningDTests(unittest.TestCase):
         if not ok:
             raise Exception("At least one lightning exited with unexpected non-zero return code")
 
+    @classmethod
+    def tearDownClass(cls):
+        """We need 100 blocks between runs, since otherwise they might see the txs from a previous run, and get very confused!"""
+        bitcoind.generate_block(100)
+
 class LightningDTests(BaseLightningDTests):
     def connect(self):
         l1 = self.node_factory.get_node()