diff --git a/bluepyopt/ephys/morphologies.py b/bluepyopt/ephys/morphologies.py
index ddaf4739..7c12b180 100644
--- a/bluepyopt/ephys/morphologies.py
+++ b/bluepyopt/ephys/morphologies.py
@@ -211,7 +211,7 @@ def replace_axon(sim=None, icell=None,
 
         for index, section in enumerate(icell.axon):
             section.L = axon_stub_length / 2
-            section.nseg = 1 + 2 * int(section.L/axon_nseg_frequency)
+            section.nseg = 1 + 2 * int(section.L / axon_nseg_frequency)
             section.diam = ais_diams[index]
             icell.axonal.append(sec=section)
             icell.all.append(sec=section)