diff --git a/matlab/+SSF/quantize8.m b/matlab/+SSF/quantize8.m
index 5921f9b3c2a745562199febfbdedffdcedc004f5..2407359ef846f8b730629f724684d6361dd2522f 100644
--- a/matlab/+SSF/quantize8.m
+++ b/matlab/+SSF/quantize8.m
@@ -1,7 +1,7 @@
 % clipLimits = [minVal,maxVal];
 function [im, clipLimits] = quantize8(im_in,clipLimits)
 
-if isa(im,'uint8')
+if isa(im_in,'uint8')
     return
 end
 im = im_in;