diff --git a/include/evalhyd/evalp.hpp b/include/evalhyd/evalp.hpp
index d4e107e2db8cd038009c2012008d152e8ad3557c..54d855714e185a3202573bd161dfdd7a45b720fc 100644
--- a/include/evalhyd/evalp.hpp
+++ b/include/evalhyd/evalp.hpp
@@ -257,6 +257,18 @@ namespace evalhyd
                     "numbers of sites"
             );
         }
+
+        if (q_thr_.size() > 0)
+        {
+            if (q_obs_.shape(0) != q_thr_.shape(0))
+            {
+                throw std::runtime_error(
+                        "observations and thresholds feature different "
+                        "numbers of sites"
+                );
+            }
+        }
+
         if (t_msk_.size() > 0)
         {
             if (q_obs_.shape(0) != t_msk_.shape(0))