diff --git a/tests/test_smt.py b/tests/test_smt.py
index b68331d..ccd8544 100644
--- a/tests/test_smt.py
+++ b/tests/test_smt.py
@@ -1,4 +1,5 @@
 from hypothesis import (
+    assume,
     given,
     strategies as st,
 )
@@ -11,12 +12,25 @@
 )
 
 
+@st.composite
+def binary_tuples(draw):
+    size = draw(st.integers(min_value=1, max_value=32))
+    v = draw(st.binary(min_size=size, max_size=size))
+    default = draw(st.binary(min_size=size, max_size=size))
+
+    # Ensure v and default are not equal
+    assume(v != default)
+
+    return (v, default)
+
+
 @given(
     k=st.binary(min_size=1, max_size=32),
-    v=st.binary(min_size=1, max_size=32),
+    values=binary_tuples(),
 )
-def test_simple_kv(k, v):
-    smt = SparseMerkleTree(key_size=len(k))
+def test_simple_kv(k, values):
+    v, default = values
+    smt = SparseMerkleTree(key_size=len(k), default=default)
     empty_root = smt.root_hash
 
     # Nothing has been added yet
diff --git a/trie/smt.py b/trie/smt.py
index 6a7fe86..795bed3 100644
--- a/trie/smt.py
+++ b/trie/smt.py
@@ -252,7 +252,7 @@ def get(self, key: bytes) -> bytes:
         value, _ = self._get(key)
 
         # Ensure that it isn't blank!
-        if value == BLANK_NODE:
+        if value == self._default:
             raise KeyError("Key does not exist")
 
         return value
@@ -261,7 +261,7 @@ def branch(self, key: bytes) -> Tuple[Hash32]:
         value, branch = self._get(key)
 
         # Ensure that it isn't blank!
-        if value == BLANK_NODE:
+        if value == self._default:
             raise KeyError("Key does not exist")
 
         return branch