diff --git a/byteops-netty/pom.xml b/byteops-netty/pom.xml
index 5e0238b..544acc3 100644
--- a/byteops-netty/pom.xml
+++ b/byteops-netty/pom.xml
@@ -22,6 +22,10 @@
       <artifactId>netty-buffer</artifactId>
       <version>${netty.version}</version>
     </dependency>
+    <dependency>
+      <groupId>org.jspecify</groupId>
+      <artifactId>jspecify</artifactId>
+    </dependency>
 
     <dependency>
       <groupId>com.digitalpetri.util</groupId>
diff --git a/byteops-netty/src/main/java/com/digitalpetri/util/package-info.java b/byteops-netty/src/main/java/com/digitalpetri/util/package-info.java
new file mode 100644
index 0000000..747c10d
--- /dev/null
+++ b/byteops-netty/src/main/java/com/digitalpetri/util/package-info.java
@@ -0,0 +1,4 @@
+@NullMarked
+package com.digitalpetri.util;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/byteops-unsigned/pom.xml b/byteops-unsigned/pom.xml
index ace05c7..f9090ac 100644
--- a/byteops-unsigned/pom.xml
+++ b/byteops-unsigned/pom.xml
@@ -22,6 +22,10 @@
       <artifactId>joou</artifactId>
       <version>${joou.version}</version>
     </dependency>
+    <dependency>
+      <groupId>org.jspecify</groupId>
+      <artifactId>jspecify</artifactId>
+    </dependency>
 
     <dependency>
       <groupId>org.junit.jupiter</groupId>
diff --git a/byteops-unsigned/src/main/java/com/digitalpetri/util/package-info.java b/byteops-unsigned/src/main/java/com/digitalpetri/util/package-info.java
new file mode 100644
index 0000000..747c10d
--- /dev/null
+++ b/byteops-unsigned/src/main/java/com/digitalpetri/util/package-info.java
@@ -0,0 +1,4 @@
+@NullMarked
+package com.digitalpetri.util;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/byteops/pom.xml b/byteops/pom.xml
index f6d6fe1..462d27d 100644
--- a/byteops/pom.xml
+++ b/byteops/pom.xml
@@ -12,6 +12,10 @@
   <artifactId>byteops</artifactId>
 
   <dependencies>
+    <dependency>
+      <groupId>org.jspecify</groupId>
+      <artifactId>jspecify</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-api</artifactId>
diff --git a/byteops/src/main/java/com/digitalpetri/util/package-info.java b/byteops/src/main/java/com/digitalpetri/util/package-info.java
new file mode 100644
index 0000000..747c10d
--- /dev/null
+++ b/byteops/src/main/java/com/digitalpetri/util/package-info.java
@@ -0,0 +1,4 @@
+@NullMarked
+package com.digitalpetri.util;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/pom.xml b/pom.xml
index b6e5688..14fe763 100644
--- a/pom.xml
+++ b/pom.xml
@@ -49,6 +49,7 @@
 
     <!-- Dependencies -->
     <joou.version>0.9.4</joou.version>
+    <jspecify.version>1.0.0</jspecify.version>
     <netty.version>4.1.112.Final</netty.version>
 
     <!-- Test Dependencies -->
@@ -85,6 +86,11 @@
         <version>${slf4j.version}</version>
         <scope>test</scope>
       </dependency>
+      <dependency>
+        <groupId>org.jspecify</groupId>
+        <artifactId>jspecify</artifactId>
+        <version>${jspecify.version}</version>
+      </dependency>
     </dependencies>
   </dependencyManagement>