diff --git a/numcodecs/delta.py b/numcodecs/delta.py
index 09a5601e..f6307312 100644
--- a/numcodecs/delta.py
+++ b/numcodecs/delta.py
@@ -64,7 +64,10 @@ def encode(self, buf):
 
         # compute differences
         # using np.subtract for in-place operations
-        np.subtract(arr[1:], arr[0:-1], out=enc[1:])
+        if arr.dtype == bool:
+            np.not_equal(arr[1:], arr[:-1], out=enc[1:])
+        else:
+            np.subtract(arr[1:], arr[:-1], out=enc[1:])
 
         return enc
 
diff --git a/numcodecs/tests/test_delta.py b/numcodecs/tests/test_delta.py
index fb5714bb..9664efee 100644
--- a/numcodecs/tests/test_delta.py
+++ b/numcodecs/tests/test_delta.py
@@ -14,6 +14,7 @@
 # mix of shapes: 1D, 2D, 3D
 # mix of orders: C, F
 arrays = [
+    np.random.randint(0, 1, size=110, dtype='?').reshape(10, 11),
     np.arange(1000, dtype='<i4'),
     np.linspace(1000, 1001, 1000, dtype='<f4').reshape(100, 10),
     np.random.normal(loc=1000, scale=1, size=(10, 10, 10)).astype('<f8'),