diff --git a/src/Varsstat.cc b/src/Varsstat.cc
index 90331bc..05c6d82 100644
--- a/src/Varsstat.cc
+++ b/src/Varsstat.cc
@@ -261,7 +261,7 @@ public:
                     if (!rsamp1.empty())
                       field2_stdvar_func(rvars1, vars2[levelID], rsamp1, divisor);
                     else
-                      fieldc_stdvar_func(rvars1, vars2[levelID], rsamp1.nsamp, divisor);
+                      fieldc_stdvar_func(rvars1, vars2[levelID], rvars1.nsamp, divisor);
                   }
                 else if (lrange) { field2_sub(rvars1, vars2[levelID]); }