diff --git a/fsl/data/image.py b/fsl/data/image.py
index 934bde5ec3900a0dd5c9009e9cfb33adf7ed4e3e..46c860a2d97954471928c4641302ab7f1248a26d 100644
--- a/fsl/data/image.py
+++ b/fsl/data/image.py
@@ -321,19 +321,19 @@ class Nifti(notifier.Notifier):
         # but we want the NIFTI codes. So we use
         # the (undocumented) nifti1.unit_codes field
         # to convert back to the raw codes.
-        xyzUnits = self.header.get_xyzt_units()[0]
-        xyzUnits = nib.nifti1.unit_codes[xyzUnits]
-
-        return xyzUnits
+        units = self.header.get_xyzt_units()[0]
+        units = nib.nifti1.unit_codes[units]
+        return units
 
 
+    @property
     def timeUnits(self):
         """Returns the NIFTI time dimension unit code. """
 
         # See xyzUnits
-        timeUnits = self.header.get_xyzt_units()[1]
-        timeUnits = nib.nifti1.unit_codes[timeUnits]
-        return timeUnits
+        units = self.header.get_xyzt_units()[1]
+        units = nib.nifti1.unit_codes[units]
+        return units
 
 
     @property