diff --git a/bumblebee/modules/traffic.py b/bumblebee/modules/traffic.py
index 2eac453..250a1a7 100644
--- a/bumblebee/modules/traffic.py
+++ b/bumblebee/modules/traffic.py
@@ -6,6 +6,8 @@ Parameters:
     * traffic.exclude: Comma-separated list of interface prefixes to exclude (defaults to "lo,virbr,docker,vboxnet,veth")
     * traffic.states: Comma-separated list of states to show (prefix with "^" to invert - i.e. ^down -> show all devices that are not in state down)
     * traffic.showname: If set to False, hide network interface name (defaults to True)
+    * traffic.format: Format string for download/upload speeds.
+                      Defaults to "{:.2f}"
 """
 
 import time
@@ -25,6 +27,7 @@ class Module(bumblebee.engine.Module):
         self._status = ""
 
         self._showname = bumblebee.util.asbool(self.parameter("showname", True))
+        self._format = self.parameter("format", "{:.2f}")
         self._prev = {}
         self._states = {}
         self._lastcheck = 0
@@ -102,8 +105,10 @@ class Module(bumblebee.engine.Module):
                 name = "traffic.{}-{}".format(direction, interface)
                 widget = self.create_widget(widgets, name, attributes={"theme.minwidth": "1000.00MB"})
                 prev = self._prev.get(name, 0)
-                speed = bumblebee.util.bytefmt((int(data[direction]) - int(prev))/timediff)
-                txtspeed ='{0}/s'.format(speed)
+                speed = bumblebee.util.bytefmt(
+                    (int(data[direction]) - int(prev))/timediff,
+                    self._format)
+                txtspeed = '{0}/s'.format(speed)
                 widget.full_text(txtspeed) 
                 self._prev[name] = data[direction]