diff --git a/java/src/org/openqa/selenium/remote/CommandInfo.java b/java/src/org/openqa/selenium/remote/CommandInfo.java
index 7280bf6a849c5..343ec9428d577 100644
--- a/java/src/org/openqa/selenium/remote/CommandInfo.java
+++ b/java/src/org/openqa/selenium/remote/CommandInfo.java
@@ -17,8 +17,10 @@
 
 package org.openqa.selenium.remote;
 
+import org.jspecify.annotations.NullMarked;
 import org.openqa.selenium.remote.http.HttpMethod;
 
+@NullMarked
 public class CommandInfo {
   private final String url;
   private final HttpMethod method;
diff --git a/java/src/org/openqa/selenium/remote/CommandPayload.java b/java/src/org/openqa/selenium/remote/CommandPayload.java
index fd3220342b3d4..fc60c4f3d2a3b 100644
--- a/java/src/org/openqa/selenium/remote/CommandPayload.java
+++ b/java/src/org/openqa/selenium/remote/CommandPayload.java
@@ -18,13 +18,16 @@
 package org.openqa.selenium.remote;
 
 import java.util.Map;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public class CommandPayload {
 
   private final String name;
-  private final Map<String, ?> parameters;
+  private final Map<String, ? extends @Nullable Object> parameters;
 
-  public CommandPayload(String name, Map<String, ?> parameters) {
+  public CommandPayload(String name, Map<String, ? extends @Nullable Object> parameters) {
     this.name = name;
     this.parameters = parameters;
   }
@@ -33,7 +36,7 @@ public String getName() {
     return name;
   }
 
-  public Map<String, ?> getParameters() {
+  public Map<String, ? extends @Nullable Object> getParameters() {
     return parameters;
   }
 }
diff --git a/java/src/org/openqa/selenium/remote/DriverCommand.java b/java/src/org/openqa/selenium/remote/DriverCommand.java
index a7df4b51dbcbd..0886fa5816a50 100644
--- a/java/src/org/openqa/selenium/remote/DriverCommand.java
+++ b/java/src/org/openqa/selenium/remote/DriverCommand.java
@@ -24,6 +24,8 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.Cookie;
 import org.openqa.selenium.Dimension;
@@ -39,6 +41,7 @@
  *
  * @author jmleyba@gmail.com (Jason Leyba)
  */
+@NullMarked
 public interface DriverCommand {
   String GET_CAPABILITIES = "getCapabilities";
   String NEW_SESSION = "newSession";
@@ -253,7 +256,7 @@ static CommandPayload SWITCH_TO_NEW_WINDOW(WindowType typeHint) {
     return new CommandPayload(SWITCH_TO_NEW_WINDOW, Map.of("type", typeHint.toString()));
   }
 
-  static CommandPayload SWITCH_TO_FRAME(Object frame) {
+  static CommandPayload SWITCH_TO_FRAME(@Nullable Object frame) {
     return new CommandPayload(SWITCH_TO_FRAME, singletonMap("id", frame));
   }