diff --git a/tests/histval_initval_file/sim_exo_lead_lag_initvalf.mod b/tests/histval_initval_file/sim_exo_lead_lag_initvalf.mod
index 044a1ee26..43e129e3e 100644
--- a/tests/histval_initval_file/sim_exo_lead_lag_initvalf.mod
+++ b/tests/histval_initval_file/sim_exo_lead_lag_initvalf.mod
@@ -25,10 +25,10 @@ end;
 
 initval_file(series = ds);
 if oo_.initval_series.dates(1) ~= dates('1Y');
-  error("Wrong initial date in oo_.initval_series");
+  error('Wrong initial date in oo_.initval_series');
 end;
 if oo_.initval_series{'x'}.data(6) ~= 0.9;
-  error("Wrond value for x"); 
+  error('Wrong value for x');
 end;
 
 perfect_foresight_setup(periods=200);
@@ -49,10 +49,10 @@ ds1 = dseries(data1, '1Y', {'c', 'cmav', 'k', 'z_backward', 'z_forward', 'x'});
 
 initval_file(series = ds1, first_obs = 3, last_obs = 210, nobs = 208);
 if oo_.initval_series.dates(1) ~= dates('3Y');
-  error("Wrong initial date in oo_.initval_series");
+  error('Wrong initial date in oo_.initval_series');
 end;
 if oo_.initval_series{'x'}.data(6) ~= 0.9;
-  error("Wrond value for x"); 
+  error('Wrong value for x');
 end;
 
 
@@ -70,10 +70,10 @@ end
 
 initval_file(series = ds1, first_obs = 3Y, last_obs = 210Y, nobs = 208);
 if oo_.initval_series.dates(1) ~= dates('3Y');
-  error("Wrong initial date in oo_.initval_series");
+  error('Wrong initial date in oo_.initval_series');
 end;
 if oo_.initval_series{'x'}.data(6) ~= 0.9;
-  error("Wrond value for x"); 
+  error('Wrong value for x');
 end;
 
 
@@ -91,10 +91,10 @@ end
 
 initval_file(series = ds1, first_simulation_period = 7);
 if oo_.initval_series.dates(1) ~= dates('3Y');
-  error("Wrong initial date in oo_.initval_series");
+  error('Wrong initial date in oo_.initval_series');
 end;
 if oo_.initval_series{'x'}.data(6) ~= 0.9;
-  error("Wrond value for x"); 
+  error('Wrong value for x');
 end;
 
 
@@ -112,10 +112,10 @@ end
 
 initval_file(series = ds1, first_simulation_period = 7Y);
 if oo_.initval_series.dates(1) ~= dates('3Y');
-  error("Wrong initial date in oo_.initval_series");
+  error('Wrong initial date in oo_.initval_series');
 end;
 if oo_.initval_series{'x'}.data(6) ~= 0.9;
-  error("Wrond value for x"); 
+  error('Wrong value for x');
 end;
 
 
diff --git a/tests/histval_initval_file_unit_tests.m b/tests/histval_initval_file_unit_tests.m
index 925ce1a57..750cf55bc 100644
--- a/tests/histval_initval_file_unit_tests.m
+++ b/tests/histval_initval_file_unit_tests.m
@@ -179,7 +179,7 @@ for i = 1:size(x,1)
 end
 fclose(fh);
 
-if ~verLessThan('matlab', '8.2')
+if (ispc && ~matlab_ver_less_than('8.2')) || (~ispc && ~matlab_ver_less_than('9.0'))
     writetable(table(x,y), 'data.xlsx')
     options = struct();
     options.datafile = 'data.xlsx';
@@ -189,18 +189,18 @@ if ~verLessThan('matlab', '8.2')
     failed_tests = my_assert(failed_tests, series.nobs == 10, ...
                              '*.xlsx file nobs test');
     num_tests = num_tests + 2;
+end
 
-    if ispc
-        writetable(table(x,y), 'data.xls')
-        options = struct();
-        options.datafile = 'data.xls';
-        series = histvalf_initvalf('INITVAL_FILE', M, options);
-        failed_tests = my_assert(failed_tests, series.init == dates('1Y'), ...
+if ispc && ~matlab_ver_less_than('8.2') % Does not work under GNU/Linux with R2020b (Unicode issue in xlsread)
+    writetable(table(x,y), 'data.xls')
+    options = struct();
+    options.datafile = 'data.xls';
+    series = histvalf_initvalf('INITVAL_FILE', M, options);
+    failed_tests = my_assert(failed_tests, series.init == dates('1Y'), ...
                              '*.xls file first_obs test');
-        failed_tests = my_assert(failed_tests, series.nobs == 10, ...        
+    failed_tests = my_assert(failed_tests, series.nobs == 10, ...
                              '*.xls file nobs test');
-        num_tests = num_tests + 2;
-    end
+    num_tests = num_tests + 2;
 end
 
 cd(getenv('TOP_TEST_DIR'));