diff --git a/curator-test-zk35/pom.xml b/curator-test-zk35/pom.xml
index a1828ff4a..222c63b2a 100644
--- a/curator-test-zk35/pom.xml
+++ b/curator-test-zk35/pom.xml
@@ -31,7 +31,7 @@
     <artifactId>curator-test-zk35</artifactId>
 
     <properties>
-        <zookeeper-35-version>3.5.7</zookeeper-35-version>
+        <zookeeper-35-version>3.8.4</zookeeper-35-version>
     </properties>
 
     <dependencies>
diff --git a/curator-test-zk36/pom.xml b/curator-test-zk36/pom.xml
index eb6758af9..e7fac23c9 100644
--- a/curator-test-zk36/pom.xml
+++ b/curator-test-zk36/pom.xml
@@ -31,7 +31,7 @@
     <artifactId>curator-test-zk36</artifactId>
 
     <properties>
-        <zookeeper-36-version>3.6.3</zookeeper-36-version>
+        <zookeeper-36-version>3.8.4</zookeeper-36-version>
     </properties>
 
     <dependencies>
diff --git a/curator-test-zk37/pom.xml b/curator-test-zk37/pom.xml
index 3f739509c..9cd5b537e 100644
--- a/curator-test-zk37/pom.xml
+++ b/curator-test-zk37/pom.xml
@@ -31,7 +31,7 @@
     <artifactId>curator-test-zk37</artifactId>
 
     <properties>
-        <zookeeper-37-version>3.7.2</zookeeper-37-version>
+        <zookeeper-37-version>3.8.4</zookeeper-37-version>
     </properties>
 
     <dependencies>
diff --git a/pom.xml b/pom.xml
index 0353ad06d..668ccb359 100644
--- a/pom.xml
+++ b/pom.xml
@@ -72,7 +72,7 @@
         <redirectTestOutputToFile>true</redirectTestOutputToFile>
 
         <!-- versions -->
-        <zookeeper-version>3.9.3</zookeeper-version>
+        <zookeeper-version>3.8.4</zookeeper-version>
         <maven-bundle-plugin-version>5.1.4</maven-bundle-plugin-version>
         <maven-compiler-plugin-version>3.10.0</maven-compiler-plugin-version>
         <maven-dependency-plugin-version>3.2.0</maven-dependency-plugin-version>