diff --git a/skgstat/Variogram.py b/skgstat/Variogram.py
index ee8d43a..38ebdc0 100644
--- a/skgstat/Variogram.py
+++ b/skgstat/Variogram.py
@@ -1149,10 +1149,7 @@ def dist_function(self):
 
     @classmethod
     def wrapped_distance_function(cls, dist_func, x, **kwargs):
-        if callable(dist_func):
-            return dist_func(x, **kwargs)
-        else:
-            return pdist(X=x, metric=dist_func, **kwargs)
+        return pdist(X=x, metric=dist_func, **kwargs)
 
     @dist_function.setter
     def dist_function(self, func):