diff --git a/pyfock/Basis.py b/pyfock/Basis.py
index 0bbadf6..69c7eb0 100644
--- a/pyfock/Basis.py
+++ b/pyfock/Basis.py
@@ -440,7 +440,7 @@ def normalizationFactorContraction(self, alphas, coeffs, norms, l, m, n, lm):
         return factor
 
 
-    def readBasisSetFromFile(key, filename):
+    def readBasisSetFromFile(self, key, filename):
         """
         Read the basis set block corresponding to a particular atom from a TURBOMOLE format file.