diff --git a/src/@dseries/merge.m b/src/@dseries/merge.m
index 25b9385a7d902b1694bc8d89e2f459cf74da24ab..f62979e2c3d35698609d508650687c33119fd289 100644
--- a/src/@dseries/merge.m
+++ b/src/@dseries/merge.m
@@ -12,7 +12,7 @@ function q = merge(o, p) % --*-- Unitary tests --*--
 % REMARKS
 % If dseries objects o and p have common variables, the variables in p take precedence.
 
-% Copyright (C) 2013-2017 Dynare Team
+% Copyright © 2013-2019 Dynare Team
 %
 % This file is part of Dynare.
 %
@@ -146,9 +146,9 @@ q.dates = q_init:q_init+(nobs(q)-1);
 %$    ts2.tag('type');
 %$    ts2.tag('type', 'A1', 'Flow');
 %$    ts3 = merge(ts1,ts2);
-%$    t(1) = 1;
+%$    t(1) = true;
 %$ catch
-%$    t = 0;
+%$    t = false;
 %$ end
 %$
 %$ if t(1)
@@ -177,9 +177,9 @@ q.dates = q_init:q_init+(nobs(q)-1);
 %$    ts2.tag('t2');
 %$    ts2.tag('t2', 'B1', 1);
 %$    ts3 = merge(ts1,ts2);
-%$    t(1) = 1;
+%$    t(1) = true;
 %$ catch
-%$    t = 0;
+%$    t = false;
 %$ end
 %$
 %$ if length(t)>1
@@ -191,3 +191,25 @@ q.dates = q_init:q_init+(nobs(q)-1);
 %$ end
 %$ T = all(t);
 %@eof:2
+
+%@test:3
+%$ % Define two dseries objects.
+%$ y = dseries(ones(4,1),'1989Q1', 'u');
+%$ z = dseries(ones(4,1),'1990Q1', 'u');
+%$
+%$ % Merge the two objects.
+%$ try
+%$    x = merge(y, z);
+%$    t(1) = true;
+%$ catch
+%$    t = false;
+%$ end
+%$
+%$ if t(1)
+%$    t(2) = dassert(x.vobs,1);
+%$    t(3) = dassert(x.name{1},'u');
+%$    t(4) = dassert(x.data, ones(8,1));
+%$    t(5) = all(x.dates==dates('1989Q1'):dates('1990Q4'));
+%$ end
+%$ T = all(t);
+%@eof:3
\ No newline at end of file