diff --git a/memoization-core/src/main/java/module-info.java b/memoization-core/src/main/java/module-info.java
index 75fdb89..c9eb356 100644
--- a/memoization-core/src/main/java/module-info.java
+++ b/memoization-core/src/main/java/module-info.java
@@ -5,7 +5,7 @@
 /**
  * The core module contains the core interfaces and utilities of memoization.java
  */
-@org.jspecify.nullness.NullMarked
+@org.jspecify.annotations.NullMarked
 module wtf.metio.memoization.core {
 
     requires com.github.spotbugs.annotations;
diff --git a/memoization-jdk/src/main/java/module-info.java b/memoization-jdk/src/main/java/module-info.java
index a99bfec..77b8c2a 100644
--- a/memoization-jdk/src/main/java/module-info.java
+++ b/memoization-jdk/src/main/java/module-info.java
@@ -5,7 +5,7 @@
 /**
  * The JDK module contains the implementation covering JDK interfaces.
  */
-@org.jspecify.nullness.NullMarked
+@org.jspecify.annotations.NullMarked
 module wtf.metio.memoization.jdk {
 
     requires wtf.metio.memoization.core;
diff --git a/memoization-jool/src/main/java/module-info.java b/memoization-jool/src/main/java/module-info.java
index 12a8099..bc11220 100644
--- a/memoization-jool/src/main/java/module-info.java
+++ b/memoization-jool/src/main/java/module-info.java
@@ -5,7 +5,7 @@
 /**
  * The jOOL module contains the implementation covering jOOL interfaces.
  */
-@org.jspecify.nullness.NullMarked
+@org.jspecify.annotations.NullMarked
 module wtf.metio.memoization.jool {
 
     requires wtf.metio.memoization.core;
diff --git a/memoization-lambda/src/main/java/module-info.java b/memoization-lambda/src/main/java/module-info.java
index 6adc689..d153443 100644
--- a/memoization-lambda/src/main/java/module-info.java
+++ b/memoization-lambda/src/main/java/module-info.java
@@ -5,7 +5,7 @@
 /**
  * The lambda module contains the implementation covering lambda interfaces.
  */
-@org.jspecify.nullness.NullMarked
+@org.jspecify.annotations.NullMarked
 module wtf.metio.memoization.lambda {
 
     requires wtf.metio.memoization.core;
diff --git a/memoization-rxjava/src/main/java/module-info.java b/memoization-rxjava/src/main/java/module-info.java
index 3755fa2..fc7f58b 100644
--- a/memoization-rxjava/src/main/java/module-info.java
+++ b/memoization-rxjava/src/main/java/module-info.java
@@ -5,7 +5,7 @@
 /**
  * The RxJava module contains the implementation covering RxJava interfaces.
  */
-@org.jspecify.nullness.NullMarked
+@org.jspecify.annotations.NullMarked
 module wtf.metio.memoization.rxjava {
 
     requires wtf.metio.memoization.core;
diff --git a/memoization-tck/pom.xml b/memoization-tck/pom.xml
index 7dc12ea..092d7e7 100755
--- a/memoization-tck/pom.xml
+++ b/memoization-tck/pom.xml
@@ -44,6 +44,10 @@
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-api</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.jspecify</groupId>
+            <artifactId>jspecify</artifactId>
+        </dependency>
     </dependencies>
 
 </project>
diff --git a/memoization-tck/src/main/java/module-info.java b/memoization-tck/src/main/java/module-info.java
index a24c75b..f3f27ef 100644
--- a/memoization-tck/src/main/java/module-info.java
+++ b/memoization-tck/src/main/java/module-info.java
@@ -5,10 +5,12 @@
 /**
  * The tck module contains re-usable test cases for the various memoization.java modules.
  */
+@org.jspecify.annotations.NullMarked
 module wtf.metio.memoization.tck {
 
-    requires org.junit.jupiter.api;
     requires wtf.metio.memoization.core;
+    requires org.junit.jupiter.api;
+    requires org.jspecify;
 
     exports wtf.metio.memoization.tck;