diff --git a/src/@dseries/firstobservedperiod.m b/src/@dseries/firstobservedperiod.m
index fa5d6a29476f12285604a51a0843cc64f4bd8e3c..92c1b239056f40aee80e660fc1b9e6a5e4545602 100644
--- a/src/@dseries/firstobservedperiod.m
+++ b/src/@dseries/firstobservedperiod.m
@@ -8,7 +8,7 @@ function d = firstobservedperiod(o) % --*-- Unitary tests --*--
 % OUTPUTS 
 % - b [dates]      First period where the N variables are observed (without NaNs).
 
-% Copyright (C) 2016 Dynare Team
+% Copyright (C) 2016-2017 Dynare Team
 %
 % This file is part of Dynare.
 %
@@ -27,6 +27,9 @@ function d = firstobservedperiod(o) % --*-- Unitary tests --*--
 
 b = ~isnan(o);
 c = find(prod(b, 2));
+if isempty(c)
+    error('No overlapping non-NaN data points found in dseries.');
+end
 d = firstdate(o)+(c(1)-1);
 
 %@test:1