diff --git a/src/main/java/org/apache/datasketches/sampling/VarOptItemsSketch.java b/src/main/java/org/apache/datasketches/sampling/VarOptItemsSketch.java
index ad46b4f04..121b6678a 100644
--- a/src/main/java/org/apache/datasketches/sampling/VarOptItemsSketch.java
+++ b/src/main/java/org/apache/datasketches/sampling/VarOptItemsSketch.java
@@ -827,8 +827,8 @@ void update(final T item, final double weight, final boolean mark) {
     if (item == null) {
       return;
     }
-    if (weight <= 0.0) {
-      throw new SketchesArgumentException("Item weights must be strictly positive: "
+    if (weight <= 0.0 || Double.isNaN(weight) || Double.isInfinite(weight)) {
+      throw new SketchesArgumentException("Item weights must be strictly positive and finite number: "
               + weight + ", for item " + item.toString());
     }
     ++n_;
diff --git a/src/test/java/org/apache/datasketches/sampling/VarOptItemsSketchTest.java b/src/test/java/org/apache/datasketches/sampling/VarOptItemsSketchTest.java
index 1331c57a7..4a9fa3a63 100644
--- a/src/test/java/org/apache/datasketches/sampling/VarOptItemsSketchTest.java
+++ b/src/test/java/org/apache/datasketches/sampling/VarOptItemsSketchTest.java
@@ -264,6 +264,18 @@ public void checkInvalidWeight() {
     vis.update("invalidWeight", -1.0); // should fail
   }
 
+  @Test(expectedExceptions = SketchesArgumentException.class)
+  public void checkNaNWeight() {
+    final VarOptItemsSketch<String> vis = VarOptItemsSketch.newInstance(5);
+    vis.update("invalidWeight", Double.NaN);
+  }
+
+  @Test(expectedExceptions = SketchesArgumentException.class)
+  public void checkInfiniteWeight() {
+    final VarOptItemsSketch<String> vis = VarOptItemsSketch.newInstance(5);
+    vis.update("invalidWeight", Double.POSITIVE_INFINITY);
+  }
+
   @Test
   public void checkCorruptSerializedWeight() {
     final VarOptItemsSketch<String> vis = VarOptItemsSketch.newInstance(24);