diff --git a/pyglance/glance/delta.py b/pyglance/glance/delta.py
index 8df09ab729ac7022fa501c922d236278ba86c464..30205d2189e7df8685686faf42d41c7affc2dfc4 100644
--- a/pyglance/glance/delta.py
+++ b/pyglance/glance/delta.py
@@ -115,7 +115,11 @@ def compute_correlation(xData, yData, goodMask, compute_r_function=pearsonr):
     # if we have enough data, try to build the correlation
     toReturn = numpy.nan
     if (good_x_data.size >= 2) and (good_y_data.size >= 2) :
-        toReturn = compute_r_function(good_x_data, good_y_data)[0]
+        with numpy.warnings.catch_warnings():
+            # If the standard deviation of good_y_data is 0.0,
+            # a warning is generated. Suppress it.
+            numpy.warnings.filterwarnings('ignore', r'invalid value encountered in float_scalars', RuntimeWarning)
+            toReturn = compute_r_function(good_x_data, good_y_data)[0]
     
     return toReturn