diff --git a/pom.xml b/pom.xml
index b5eab90fe8cb456d4ff6cb679cac6595de2e3168..4d1acb81827cc8aef564740c50a7a90f8875938f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -125,7 +125,7 @@
 		<dependency>
 			<groupId>com.carrotsearch</groupId>
 			<artifactId>hppc</artifactId>
-			<version>0.6.1</version>
+			<version>0.7.1</version>
 		</dependency>
 	</dependencies>
 
diff --git a/src/main/java/teetime/stage/FileExtensionSwitch.java b/src/main/java/teetime/stage/FileExtensionSwitch.java
index 77415a47d8e8bdd5987b8b238d04996babe1d789..cecf2598e410c5414172b0235cfdbf9398adda53 100644
--- a/src/main/java/teetime/stage/FileExtensionSwitch.java
+++ b/src/main/java/teetime/stage/FileExtensionSwitch.java
@@ -20,14 +20,15 @@ import java.io.File;
 import teetime.framework.AbstractConsumerStage;
 import teetime.framework.OutputPort;
 
-import com.carrotsearch.hppc.ObjectObjectOpenHashMap;
+import com.carrotsearch.hppc.ObjectObjectHashMap;
+import com.carrotsearch.hppc.ObjectObjectMap;
 import com.google.common.io.Files;
 
 public final class FileExtensionSwitch extends AbstractConsumerStage<File> {
 
 	private final OutputPort<File> unknownFileExtensionOutputPort = createOutputPort(File.class);
 
-	private final ObjectObjectOpenHashMap<String, OutputPort<File>> fileExtensions = new ObjectObjectOpenHashMap<String, OutputPort<File>>();
+	private final ObjectObjectMap<String, OutputPort<File>> fileExtensions = new ObjectObjectHashMap<String, OutputPort<File>>();
 
 	@Override
 	protected void execute(final File file) {
diff --git a/src/main/java/teetime/stage/util/CountingMap.java b/src/main/java/teetime/stage/util/CountingMap.java
index de1714722dc016fd1737703714fb8fe1c05e6c66..8ef17003eee9dc3b32d57d09c66b7b819ab0a442 100644
--- a/src/main/java/teetime/stage/util/CountingMap.java
+++ b/src/main/java/teetime/stage/util/CountingMap.java
@@ -15,8 +15,8 @@
  */
 package teetime.stage.util;
 
+import com.carrotsearch.hppc.ObjectIntHashMap;
 import com.carrotsearch.hppc.ObjectIntMap;
-import com.carrotsearch.hppc.ObjectIntOpenHashMap;
 import com.carrotsearch.hppc.procedures.ObjectIntProcedure;
 
 /**
@@ -31,7 +31,7 @@ import com.carrotsearch.hppc.procedures.ObjectIntProcedure;
  */
 public final class CountingMap<T> {
 
-	private final ObjectIntMap<T> map = new ObjectIntOpenHashMap<T>();
+	private final ObjectIntMap<T> map = new ObjectIntHashMap<T>();
 
 	/**
 	 * Increments the value of key by one.