diff --git a/matlab/utilities/tests/mtest.m b/matlab/utilities/tests/mtest.m
index af2819a14..403e85061 100644
--- a/matlab/utilities/tests/mtest.m
+++ b/matlab/utilities/tests/mtest.m
@@ -74,6 +74,9 @@ for i=1:nn
     fprintf(tid,['try\n']);
     for j=b1(i):b2(i)
         str = sprintf('%s \n',file{j}(4:end));
+        if isoctave
+            str = regexprep(str, '%', '%%');
+        end
         fprintf(tid,str);
     end
     fprintf(tid,['LOG = NaN;\n']);