diff --git a/tools/validate.py b/tools/validate.py
index 8b8a9e82c8eccd10243ba1232984c080c873900d..4f7800426834d52006e8785a5acf21daabd889e5 100644
--- a/tools/validate.py
+++ b/tools/validate.py
@@ -69,9 +69,9 @@ def calculate_similarity(u, v, data_type=np.float64):
     norm = u_norm * v_norm
     if norm == 0:
         if u_norm == 0 and v_norm == 0:
-            return 1
+            return data_type(1)
         else:
-            return 0
+            return data_type(0)
     else:
         return np.dot(u, v) / norm