diff --git a/+ndr/+format/+neuropixelsGLX/read.m b/+ndr/+format/+neuropixelsGLX/read.m
index 35460fa..cadd301 100644
--- a/+ndr/+format/+neuropixelsGLX/read.m
+++ b/+ndr/+format/+neuropixelsGLX/read.m
@@ -44,8 +44,8 @@
         binfilename (1,:) char {mustBeFile}
         t0 (1,1) double
         t1 (1,1) double
-        options.numChans (1,1) {mustBeInteger, mustBePositive} = 0
-        options.SR (1,1) {mustBeNumeric, mustBePositive} = 0
+        options.numChans (1,1) {mustBeInteger, mustBeNonnegative} = 0
+        options.SR (1,1) {mustBeNumeric, mustBeNonnegative} = 0
         options.channels (1,:) {mustBeNumeric, mustBeInteger, mustBePositive} = []
     end