diff --git a/matlab/@dynSeries/plus.m b/matlab/@dynSeries/plus.m
index d60d51d6a433deace8ebd81b06a0d20c7ff8fd0e..dd0e1037f7c6601a2c348afc9f35f3b64e0a45bd 100644
--- a/matlab/@dynSeries/plus.m
+++ b/matlab/@dynSeries/plus.m
@@ -173,3 +173,52 @@ A.data = bsxfun(@plus,B.data,C.data);
 %$ end
 %$ T = all(t);
 %@eof:3
+
+
+%@test:4
+%$ t = zeros(7,1);
+%$
+%$ try
+%$     ts = dynSeries(transpose(1:5),'1950q1',{'Output'}, {'Y_t'});
+%$     us = dynSeries(transpose(1:5),'1949q4',{'Consumption'}, {'C_t'});
+%$     vs = ts+us;
+%$     t(1) = 1;
+%$ catch
+%$     t = 0;
+%$ end
+%$
+%$ if length(t)>1
+%$     t(2) = dyn_assert(ts.freq,4);
+%$     t(3) = dyn_assert(us.freq,4);
+%$     t(4) = dyn_assert(ts.init.time,[1950, 1]);
+%$     t(5) = dyn_assert(us.init.time,[1949, 4]);
+%$     t(6) = dyn_assert(vs.init.time,[1949, 4]);
+%$     t(7) = dyn_assert(vs.nobs,6);
+%$ end
+%$
+%$ T = all(t);
+%@eof:4
+
+%@test:5
+%$ t = zeros(7,1);
+%$
+%$ try
+%$     ts = dynSeries(transpose(1:5),'1950q1',{'Output'}, {'Y_t'});
+%$     us = dynSeries(transpose(1:7),'1950q1',{'Consumption'}, {'C_t'});
+%$     vs = ts+us;
+%$     t(1) = 1;
+%$ catch
+%$     t = 0;
+%$ end
+%$
+%$ if length(t)>1
+%$     t(2) = dyn_assert(ts.freq,4);
+%$     t(3) = dyn_assert(us.freq,4);
+%$     t(4) = dyn_assert(ts.init.time,[1950, 1]);
+%$     t(5) = dyn_assert(us.init.time,[1950, 1]);
+%$     t(6) = dyn_assert(vs.init.time,[1950, 1]);
+%$     t(7) = dyn_assert(vs.nobs,7);
+%$ end
+%$
+%$ T = all(t);
+%@eof:5
\ No newline at end of file