diff --git a/pykat/__init__.py b/pykat/__init__.py
index b21af8721a9e6dc26939f4e65a259a8ee6cf3fbf..420f930582e986de5ef5cb5b78e3ad679152ea11 100644
--- a/pykat/__init__.py
+++ b/pykat/__init__.py
@@ -3,7 +3,7 @@ from __future__ import division
 from __future__ import print_function
 from __future__ import unicode_literals
 
-__version__ = "0.8.0"
+__version__ = "0.8.1"
 
 # This flag is used to switch on the gui features in pkat at import time
 USE_GUI = False
diff --git a/pykat/detectors.py b/pykat/detectors.py
index 6b8ce2f8af669bd6a427ea1bd63f2f5ae4afd090..2628531b5e6192101fc036e2f2af7468b0fc918d 100644
--- a/pykat/detectors.py
+++ b/pykat/detectors.py
@@ -246,7 +246,7 @@ class beam(Detector1):
         if len(values) == 3:
             return beam(values[1], node, alternate_beam=alt_beam)
         elif len(values) == 4:
-            return beam(values[1], node, alternate_beam=alt_beam, frequency=pykat.SIfloat.SIfloat(values[2]))
+            return beam(values[1], node, alternate_beam=alt_beam, frequency=SIfloat(values[2]))
         else:
             raise pkex.BasePyKatException('Beam detector code "{0}" is not a valid FINESSE command'.format(text))