matplotlib
diff --git a/‎lib/matplotlib/colorbar.py‎
Lines changed: 15 additions & 4 deletions b/‎lib/matplotlib/colorbar.py‎
Lines changed: 15 additions & 4 deletions
@@ -218,6 +218,7 @@ def _set_ticks_on_axis_warn(*args, **kw):
     # set_xticks set_yticks by _patch_ax
     warnings.warn("Use the colorbar set_ticks() method instead.")
 
+
 class ColorbarAutoLocator(ticker.MaxNLocator):
     """ AutoLocator for Colorbar
     """
@@ -228,12 +229,12 @@ def __init__(self, colorbar, *args, **kwargs):
         steps = [1, 2, 2.5, 5, 10]
         ticker.MaxNLocator.__init__(self, nbins=nbins, steps=steps)
 
-
     def tick_values(self, vmin, vmax):
         vmin = max(vmin, self._colorbar.norm.vmin)
         vmax = min(vmax, self._colorbar.norm.vmax)
         return ticker.MaxNLocator.tick_values(self, vmin, vmax)
 
+
 class ColorbarBase(cm.ScalarMappable):
     '''
     Draw a colorbar in an existing axes.
@@ -394,7 +395,6 @@ def config_axis(self):
 
         self._set_label()
 
-
     def _get_ticker_locator_formatter(self):
         locator = self.locator
         formatter = self.formatter
@@ -426,6 +426,16 @@ def _get_ticker_locator_formatter(self):
                 locator = ticker.FixedLocator(b, nbins=10)
         return locator, formatter
 
+    def _use_adjustable(self):
+        """
+        Return if we should use an adjustable tick locator or a fixed
+        one.  (check is used twice so factored out here...)
+        """
+        return (self.boundaries is None
+                and self.values is None
+                and not isinstance(self.norm, colors.BoundaryNorm))
+
+
     def update_ticks(self):
         """
         Force the update of the ticks and ticklabels. This must be
@@ -435,7 +445,8 @@ def update_ticks(self):
         # get the locator and formatter.  Defaults to
         # self.locator if not None..
         locator, formatter = self._get_ticker_locator_formatter()
-        if self.boundaries is None and self.values is None:
+
+        if self._use_adjustable():
             _log.debug('Using adjustable locator on colorbar')
             if self.orientation == 'vertical':
                 ax.yaxis.set_major_locator(locator)
@@ -898,7 +909,7 @@ def _mesh(self):
         # scale this up for Auto tick location.  Otherwise we
         # want to keep normalized between 0 and 1 and use manual tick
         # locations.
-        if self.boundaries is None and self.values is None:
+        if self._use_adjustable():
             dy = self.vmax - self.vmin
             y = y * dy + self.vmin
             x = x * dy