diff --git a/CHANGELOG.MD b/CHANGELOG.MD
index 06dda63..0e5d6a0 100644
--- a/CHANGELOG.MD
+++ b/CHANGELOG.MD
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- [JHP-95]: Support for XNAT 1.9.0.
+
 ### Fixed
 
 - [JHP-103]: Check for xdat_user table before creating JupyterHub user account. 
@@ -90,5 +94,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [JHP-89]: https://radiologics.atlassian.net/jira/software/c/projects/JHP/issues/JHP-89
 [JHP-91]: https://radiologics.atlassian.net/jira/software/c/projects/JHP/issues/JHP-91
 [JHP-92]: https://radiologics.atlassian.net/jira/software/c/projects/JHP/issues/JHP-92
+[JHP-95]: https://radiologics.atlassian.net/jira/software/c/projects/JHP/issues/JHP-95
 [JHP-103]: https://radiologics.atlassian.net/jira/software/c/projects/JHP/issues/JHP-103
 [JHP-112]: https://radiologics.atlassian.net/jira/software/c/projects/JHP/issues/JHP-112
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index aea8fc9..1e6e133 100644
--- a/build.gradle
+++ b/build.gradle
@@ -3,7 +3,7 @@
  */
 plugins {
     id "java"
-    id "org.nrg.xnat.build.xnat-data-builder" version "1.8.10"
+    id "org.nrg.xnat.build.xnat-data-builder" version "1.9.0"
     id "io.freefair.lombok" version "6.0.0-m2"
     id "jacoco"
 }
@@ -27,7 +27,7 @@ configurations {
 }
 
 dependencies {
-    xnatProvided platform("org.nrg:parent:1.8.10")
+    xnatProvided platform("org.nrg:parent:1.9.0")
     xnatProvided "org.nrg:framework"
     xnatProvided "org.nrg.xnat:xnat-data-models"
     xnatProvided "org.nrg.xnat:web"
@@ -38,6 +38,11 @@ dependencies {
 
 dependencies {
     implementation 'org.projectlombok:lombok:1.18.24'
+    implementation('io.projectreactor:reactor-core') {
+        version {
+            strictly "2.0.8.RELEASE"
+        }
+    }
     testImplementation "com.fasterxml.jackson.datatype:jackson-datatype-guava"
     testImplementation "junit:junit"
     testImplementation "com.h2database:h2"
diff --git a/src/main/java/org/nrg/xnatx/plugins/jupyterhub/events/JupyterServerEvent.java b/src/main/java/org/nrg/xnatx/plugins/jupyterhub/events/JupyterServerEvent.java
index 192f727..7f3c8e9 100644
--- a/src/main/java/org/nrg/xnatx/plugins/jupyterhub/events/JupyterServerEvent.java
+++ b/src/main/java/org/nrg/xnatx/plugins/jupyterhub/events/JupyterServerEvent.java
@@ -6,7 +6,7 @@
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 import lombok.extern.slf4j.Slf4j;
-import org.jetbrains.annotations.Nullable;
+import javax.annotation.Nullable;
 import org.nrg.xdat.XDAT;
 import org.nrg.xnatx.plugins.jupyterhub.models.JupyterServerEventTrackingLog;
 
diff --git a/src/main/java/org/nrg/xnatx/plugins/jupyterhub/models/JupyterServerEventTrackingLog.java b/src/main/java/org/nrg/xnatx/plugins/jupyterhub/models/JupyterServerEventTrackingLog.java
index 8322d0b..35d0e37 100644
--- a/src/main/java/org/nrg/xnatx/plugins/jupyterhub/models/JupyterServerEventTrackingLog.java
+++ b/src/main/java/org/nrg/xnatx/plugins/jupyterhub/models/JupyterServerEventTrackingLog.java
@@ -3,7 +3,7 @@
 import com.fasterxml.jackson.annotation.JsonInclude;
 import lombok.*;
 import lombok.extern.slf4j.Slf4j;
-import org.jetbrains.annotations.NotNull;
+import javax.validation.constraints.NotNull;
 import org.nrg.xnatx.plugins.jupyterhub.events.JupyterServerEventI;
 
 import javax.annotation.Nullable;
diff --git a/src/main/java/org/nrg/xnatx/plugins/jupyterhub/services/impl/HibernateUserOptionsEntityService.java b/src/main/java/org/nrg/xnatx/plugins/jupyterhub/services/impl/HibernateUserOptionsEntityService.java
index 9a7c527..910a484 100644
--- a/src/main/java/org/nrg/xnatx/plugins/jupyterhub/services/impl/HibernateUserOptionsEntityService.java
+++ b/src/main/java/org/nrg/xnatx/plugins/jupyterhub/services/impl/HibernateUserOptionsEntityService.java
@@ -1,7 +1,7 @@
 package org.nrg.xnatx.plugins.jupyterhub.services.impl;
 
 import lombok.extern.slf4j.Slf4j;
-import org.jetbrains.annotations.NotNull;
+import javax.validation.constraints.NotNull;
 import org.nrg.framework.orm.hibernate.AbstractHibernateEntityService;
 import org.nrg.xnatx.plugins.jupyterhub.entities.UserOptionsEntity;
 import org.nrg.xnatx.plugins.jupyterhub.repositories.UserOptionsDao;
diff --git a/src/test/java/org/nrg/xnatx/plugins/jupyterhub/config/HibernateConfig.java b/src/test/java/org/nrg/xnatx/plugins/jupyterhub/config/HibernateConfig.java
index b75ca44..863c76f 100644
--- a/src/test/java/org/nrg/xnatx/plugins/jupyterhub/config/HibernateConfig.java
+++ b/src/test/java/org/nrg/xnatx/plugins/jupyterhub/config/HibernateConfig.java
@@ -8,8 +8,8 @@
 import org.springframework.beans.factory.config.PropertiesFactoryBean;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.orm.hibernate4.HibernateTransactionManager;
-import org.springframework.orm.hibernate4.LocalSessionFactoryBean;
+import org.springframework.orm.hibernate5.HibernateTransactionManager;
+import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
 import org.springframework.transaction.support.ResourceTransactionManager;
 
 import javax.sql.DataSource;
diff --git a/src/test/java/org/nrg/xnatx/plugins/jupyterhub/config/ObjectMapperConfig.java b/src/test/java/org/nrg/xnatx/plugins/jupyterhub/config/ObjectMapperConfig.java
index 255b1bf..a42772a 100644
--- a/src/test/java/org/nrg/xnatx/plugins/jupyterhub/config/ObjectMapperConfig.java
+++ b/src/test/java/org/nrg/xnatx/plugins/jupyterhub/config/ObjectMapperConfig.java
@@ -5,7 +5,7 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.datatype.guava.GuavaModule;
-import com.fasterxml.jackson.datatype.hibernate4.Hibernate4Module;
+import com.fasterxml.jackson.datatype.hibernate5.Hibernate5Module;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
@@ -19,7 +19,7 @@ public Jackson2ObjectMapperBuilder objectMapperBuilder() {
                 .failOnEmptyBeans(false)
                 .featuresToEnable(JsonParser.Feature.ALLOW_SINGLE_QUOTES, JsonParser.Feature.ALLOW_YAML_COMMENTS)
                 .featuresToDisable(SerializationFeature.FAIL_ON_EMPTY_BEANS, SerializationFeature.WRITE_NULL_MAP_VALUES)
-                .modulesToInstall(new Hibernate4Module(), new GuavaModule());
+                .modulesToInstall(new Hibernate5Module(), new GuavaModule());
     }
 
     @Bean