diff --git a/pyerrors/pyerrors.py b/pyerrors/pyerrors.py
index 6039b412..2e14d2e0 100644
--- a/pyerrors/pyerrors.py
+++ b/pyerrors/pyerrors.py
@@ -476,7 +476,7 @@ class Obs:
             pickle.dump(self, fb)
 
     def __float__(self):
-        return self.value
+        return float(self.value)
 
     def __repr__(self):
         return 'Obs[' + str(self) + ']'