diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index 3fe2043ac98..59f5a722a1d 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -297,6 +297,8 @@ Other
 
 * LUCENE-9391: Upgrade HPPC to 0.8.2. (Haoyu Zhai)
 
+* LUCENE-10021: Upgrade HPPC to 0.9.0. Replace usage of ...ScatterMap to ...HashMap. (Patrick Zhai)
+
 * LUCENE-8768: Fix Javadocs build in Java 11. (Namgyu Kim)
 
 * LUCENE-9092: upgrade randomizedtesting to 2.7.5 (Dawid Weiss)
diff --git a/lucene/facet/src/java/org/apache/lucene/facet/LongValueFacetCounts.java b/lucene/facet/src/java/org/apache/lucene/facet/LongValueFacetCounts.java
index 44f2dabd694..71ec7cad883 100644
--- a/lucene/facet/src/java/org/apache/lucene/facet/LongValueFacetCounts.java
+++ b/lucene/facet/src/java/org/apache/lucene/facet/LongValueFacetCounts.java
@@ -17,7 +17,7 @@
 
 package org.apache.lucene.facet;
 
-import com.carrotsearch.hppc.LongIntScatterMap;
+import com.carrotsearch.hppc.LongIntHashMap;
 import com.carrotsearch.hppc.cursors.LongIntCursor;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -52,7 +52,7 @@ public class LongValueFacetCounts extends Facets {
   private final int[] counts = new int[1024];
 
   /** Used for all values that are >= 1K. */
-  private final LongIntScatterMap hashCounts = new LongIntScatterMap();
+  private final LongIntHashMap hashCounts = new LongIntHashMap();
 
   /** Field being counted. */
   private final String field;
diff --git a/lucene/facet/src/java/org/apache/lucene/facet/StringValueFacetCounts.java b/lucene/facet/src/java/org/apache/lucene/facet/StringValueFacetCounts.java
index 1c66042c9ff..bf51e30dbc8 100644
--- a/lucene/facet/src/java/org/apache/lucene/facet/StringValueFacetCounts.java
+++ b/lucene/facet/src/java/org/apache/lucene/facet/StringValueFacetCounts.java
@@ -16,7 +16,7 @@
  */
 package org.apache.lucene.facet;
 
-import com.carrotsearch.hppc.IntIntScatterMap;
+import com.carrotsearch.hppc.IntIntHashMap;
 import com.carrotsearch.hppc.cursors.IntIntCursor;
 import java.io.IOException;
 import java.util.Arrays;
@@ -67,7 +67,7 @@ public class StringValueFacetCounts extends Facets {
   private final SortedSetDocValues docValues;
 
   private final int[] denseCounts;
-  private final IntIntScatterMap sparseCounts;
+  private final IntIntHashMap sparseCounts;
 
   private final int cardinality;
   private int totalDocCount;
@@ -110,7 +110,7 @@ public class StringValueFacetCounts extends Facets {
         // If our result set is < 10% of the index, we collect sparsely (use hash map). This
         // heuristic is borrowed from IntTaxonomyFacetCounts:
         if (totalHits < totalDocs / 10) {
-          sparseCounts = new IntIntScatterMap();
+          sparseCounts = new IntIntHashMap();
           denseCounts = null;
         } else {
           sparseCounts = null;
diff --git a/lucene/facet/src/java/org/apache/lucene/facet/taxonomy/IntTaxonomyFacets.java b/lucene/facet/src/java/org/apache/lucene/facet/taxonomy/IntTaxonomyFacets.java
index 7d4e5d6149c..fc7124f686d 100644
--- a/lucene/facet/src/java/org/apache/lucene/facet/taxonomy/IntTaxonomyFacets.java
+++ b/lucene/facet/src/java/org/apache/lucene/facet/taxonomy/IntTaxonomyFacets.java
@@ -16,7 +16,7 @@
  */
 package org.apache.lucene.facet.taxonomy;
 
-import com.carrotsearch.hppc.IntIntScatterMap;
+import com.carrotsearch.hppc.IntIntHashMap;
 import com.carrotsearch.hppc.cursors.IntIntCursor;
 import java.io.IOException;
 import java.util.Map;
@@ -34,7 +34,7 @@ public abstract class IntTaxonomyFacets extends TaxonomyFacets {
   /** Per-ordinal value. */
   private final int[] values;
 
-  private final IntIntScatterMap sparseValues;
+  private final IntIntHashMap sparseValues;
 
   /** Sole constructor. */
   protected IntTaxonomyFacets(
@@ -43,7 +43,7 @@ public abstract class IntTaxonomyFacets extends TaxonomyFacets {
     super(indexFieldName, taxoReader, config);
 
     if (useHashTable(fc, taxoReader)) {
-      sparseValues = new IntIntScatterMap();
+      sparseValues = new IntIntHashMap();
       values = null;
     } else {
       sparseValues = null;
diff --git a/lucene/licenses/hppc-0.8.2.jar.sha1 b/lucene/licenses/hppc-0.8.2.jar.sha1
deleted file mode 100644
index a73358b9c66..00000000000
--- a/lucene/licenses/hppc-0.8.2.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-ccb3ef933ead6b5d766fa571582ddb9b447e48c4
diff --git a/lucene/licenses/hppc-0.9.0.jar.sha1 b/lucene/licenses/hppc-0.9.0.jar.sha1
new file mode 100644
index 00000000000..0cd847ea7e9
--- /dev/null
+++ b/lucene/licenses/hppc-0.9.0.jar.sha1
@@ -0,0 +1 @@
+fcc952fb6d378266b943bef9f15e67a4d45cfa88
diff --git a/versions.lock b/versions.lock
index 5bfeac5561a..af19c24c0fa 100644
--- a/versions.lock
+++ b/versions.lock
@@ -1,5 +1,5 @@
 # Run ./gradlew --write-locks to regenerate this file
-com.carrotsearch:hppc:0.8.2 (1 constraints: 0c050536)
+com.carrotsearch:hppc:0.9.0 (1 constraints: 0b050636)
 com.carrotsearch.randomizedtesting:randomizedtesting-runner:2.7.6 (1 constraints: 11051036)
 com.ibm.icu:icu4j:68.2 (1 constraints: e4041f31)
 commons-codec:commons-codec:1.13 (1 constraints: d904f430)
diff --git a/versions.props b/versions.props
index 4b5a2c239d0..201f436ed95 100644
--- a/versions.props
+++ b/versions.props
@@ -1,5 +1,5 @@
 com.carrotsearch.randomizedtesting:*=2.7.6
-com.carrotsearch:hppc=0.8.2
+com.carrotsearch:hppc=0.9.0
 com.github.ben-manes.caffeine:caffeine=2.8.4
 com.google.errorprone:*=2.4.0
 com.google.guava:guava=25.1-jre