diff --git a/extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/theta/SketchEstimatePostAggregator.java b/extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/theta/SketchEstimatePostAggregator.java
index 6bb908dff6a..496f7afb69f 100644
--- a/extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/theta/SketchEstimatePostAggregator.java
+++ b/extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/theta/SketchEstimatePostAggregator.java
@@ -141,9 +141,18 @@ public class SketchEstimatePostAggregator implements PostAggregator
     if (!name.equals(that.name)) {
       return false;
     }
-    if (errorBoundsStdDev != that.errorBoundsStdDev) {
+    
+    if (errorBoundsStdDev == null ^ that.errorBoundsStdDev == null) {
+      // one of the two stddevs (not both) are null
       return false;
     }
+    
+    if (errorBoundsStdDev != null && that.errorBoundsStdDev != null && 
+        errorBoundsStdDev.intValue() != that.errorBoundsStdDev.intValue()) {
+      // neither stddevs are null, Integer values don't match
+      return false;
+    }
+
     return field.equals(that.field);
 
   }
diff --git a/extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/theta/SketchMergeAggregatorFactory.java b/extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/theta/SketchMergeAggregatorFactory.java
index b2514f754a8..5382562dd86 100644
--- a/extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/theta/SketchMergeAggregatorFactory.java
+++ b/extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/theta/SketchMergeAggregatorFactory.java
@@ -161,11 +161,19 @@ public class SketchMergeAggregatorFactory extends SketchAggregatorFactory
     if (shouldFinalize != that.shouldFinalize) {
       return false;
     }
-    if (errorBoundsStdDev != that.errorBoundsStdDev) {
+    
+    if (errorBoundsStdDev == null ^ that.errorBoundsStdDev == null) {
+      // one of the two stddevs (not both) are null
       return false;
     }
-    return isInputThetaSketch == that.isInputThetaSketch;
 
+    if (errorBoundsStdDev != null && that.errorBoundsStdDev != null && 
+        errorBoundsStdDev.intValue() != that.errorBoundsStdDev.intValue()) {
+      // neither stddevs are null, Integer values don't match
+      return false;
+    }
+    
+    return isInputThetaSketch == that.isInputThetaSketch;
   }
 
   @Override