diff --git a/src/main/java/gov/usgs/earthquake/nshmp/www/services/DeaggEpsilonService.java b/src/main/java/gov/usgs/earthquake/nshmp/www/services/DeaggEpsilonService.java
index 7e584a1cd1989b54382a824515e966e620c83e6a..ada6f9dc38fb48616c06a8cb7c0e4fae104d54c5 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/www/services/DeaggEpsilonService.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/www/services/DeaggEpsilonService.java
@@ -6,6 +6,8 @@ import java.util.List;
 import java.util.concurrent.ExecutionException;
 import java.util.function.Function;
 
+import javax.inject.Singleton;
+
 import com.google.common.base.Stopwatch;
 import com.google.common.collect.ImmutableList;
 
@@ -32,6 +34,7 @@ import io.micronaut.http.HttpResponse;
  *
  * @author U.S. Geological Survey
  */
+@Singleton
 public final class DeaggEpsilonService {
 
   /* Developer notes: See HazardService. */
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/www/services/HazardService.java b/src/main/java/gov/usgs/earthquake/nshmp/www/services/HazardService.java
index 60bb6ff58d9feb0880d43ad247e89c748ecbee7b..5210a78fe7feba6bf8592a1d3f9e78402485cd72 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/www/services/HazardService.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/www/services/HazardService.java
@@ -11,6 +11,8 @@ import java.util.Map;
 import java.util.concurrent.ExecutionException;
 import java.util.function.Function;
 
+import javax.inject.Singleton;
+
 import com.google.common.base.Stopwatch;
 
 import gov.usgs.earthquake.nshmp.calc.CalcConfig;
@@ -43,6 +45,7 @@ import io.micronaut.http.HttpResponse;
  *
  * @author U.S. Geological Survey
  */
+@Singleton
 public final class HazardService {
 
   private static final String NAME = "Hazard Service";
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/www/services/RateService.java b/src/main/java/gov/usgs/earthquake/nshmp/www/services/RateService.java
index 4c08ef08708998ebc6c131f756de1d395eb9f68f..54656ceb7a1f6dad3ffec5433a3e1a5dc994c378 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/www/services/RateService.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/www/services/RateService.java
@@ -6,6 +6,8 @@ import java.util.Optional;
 import java.util.concurrent.ExecutionException;
 import java.util.stream.Collectors;
 
+import javax.inject.Singleton;
+
 import com.google.common.base.Stopwatch;
 import com.google.common.util.concurrent.ListenableFuture;
 
@@ -35,6 +37,7 @@ import io.micronaut.http.HttpResponse;
  *
  * @author U.S. Geological Survey
  */
+@Singleton
 public final class RateService {
 
   /*
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/www/services/ServletUtil.java b/src/main/java/gov/usgs/earthquake/nshmp/www/services/ServletUtil.java
index 3a4a71851b67dfd3661389848fdb797f0390913c..3c277e2bad98b422863dceea9328c05f0a7229db 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/www/services/ServletUtil.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/www/services/ServletUtil.java
@@ -15,6 +15,8 @@ import java.util.HashMap;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
+import javax.inject.Singleton;
+
 import com.google.common.base.Stopwatch;
 import com.google.common.util.concurrent.ListeningExecutorService;
 import com.google.common.util.concurrent.MoreExecutors;
@@ -42,6 +44,7 @@ import io.micronaut.runtime.event.annotation.EventListener;
  *
  * @author U.S. Geological Survey
  */
+@Singleton
 public class ServletUtil {
 
   public static final Gson GSON;
diff --git a/src/main/java/gov/usgs/earthquake/nshmp/www/services/SourceServices.java b/src/main/java/gov/usgs/earthquake/nshmp/www/services/SourceServices.java
index ce54b6b3ae56513399a705922c5fccd1653422fb..eb1fd728af424cf5210fd1ebe57d197760d8eaa8 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/www/services/SourceServices.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/www/services/SourceServices.java
@@ -3,6 +3,8 @@ package gov.usgs.earthquake.nshmp.www.services;
 import java.util.Map;
 import java.util.Set;
 
+import javax.inject.Singleton;
+
 import com.google.common.base.Stopwatch;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
@@ -25,6 +27,7 @@ import io.micronaut.http.HttpResponse;
  *
  * @author U.S. Geological Survey
  */
+@Singleton
 public class SourceServices {
 
   private static final String NAME = "Source Model";