diff --git a/src/+dseries/initialize.m b/src/+dseries/initialize.m
index b751b13e2d1ff62dcd564f93c3a876dad5f0d06b..be8a58eaf365717980639b370fc4cf6d1ffccc16 100644
--- a/src/+dseries/initialize.m
+++ b/src/+dseries/initialize.m
@@ -20,13 +20,13 @@ dseries_src_root = strrep(which('dseries.initialize'),'+dseries/initialize.m',''
 
 % Check that the x13 binary is available
 nox13 = false;
-if isunix()
-    [status, ~] = system('which x13as');
-    if status && ~(exist([dseries_src_root '../externals/x13/linux/64/x13as'], 'file') && exist([dseries_src_root '../externals/x13/linux/32/x13as'], 'file'))
+if ismac()
+    if ~exist([dseries_src_root '../externals/x13/osx/64/x13as'], 'file')
         nox13 = true;
     end
-elseif ismac()
-    if ~exist([dseries_src_root '../externals/x13/osx/64/x13as'], 'file')
+elseif isunix()
+    [status, ~] = system('which x13as');
+    if status && ~(exist([dseries_src_root '../externals/x13/linux/64/x13as'], 'file') && exist([dseries_src_root '../externals/x13/linux/32/x13as'], 'file'))
         nox13 = true;
     end
 elseif ispc()