diff --git a/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Metrics/AggregationManager.cs b/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Metrics/AggregationManager.cs
index d181fbdf9a666..aaf6cb6a20fe5 100644
--- a/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Metrics/AggregationManager.cs
+++ b/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Metrics/AggregationManager.cs
@@ -302,7 +302,8 @@ private void RemoveInstrumentState(Instrument instrument, InstrumentState state)
                 {
                     lock (this)
                     {
-                        return (!CheckTimeSeriesAllowed() || !CheckHistogramAllowed()) ?
+                        // checking currentHistograms first because avoiding unexpected increment of TimeSeries count.
+                        return (!CheckHistogramAllowed() || !CheckTimeSeriesAllowed()) ?
                             null :
                             new ExponentialHistogramAggregator(s_defaultHistogramConfig);
                     }