diff --git a/spec/src/main/java/io/a2a/util/Utils.java b/spec/src/main/java/io/a2a/util/Utils.java
index ca0610b1..79236557 100644
--- a/spec/src/main/java/io/a2a/util/Utils.java
+++ b/spec/src/main/java/io/a2a/util/Utils.java
@@ -38,11 +38,6 @@ public class Utils {
 
     private static final Logger log = Logger.getLogger(Utils.class.getName());
 
-    /**
-     * Specification version constant for deprecation annotations.
-     */
-    public static final String SPEC_VERSION_1_0 = "1.0";
-
     /**
      * Returns the provided value if non-null, otherwise returns the default value.
      * <p>
diff --git a/transport/grpc/src/test/java/io/a2a/transport/grpc/handler/GrpcHandlerTest.java b/transport/grpc/src/test/java/io/a2a/transport/grpc/handler/GrpcHandlerTest.java
index ad9b879f..77a2c955 100644
--- a/transport/grpc/src/test/java/io/a2a/transport/grpc/handler/GrpcHandlerTest.java
+++ b/transport/grpc/src/test/java/io/a2a/transport/grpc/handler/GrpcHandlerTest.java
@@ -966,7 +966,6 @@ public void testVersionNotSupportedErrorOnSendMessage() throws Exception {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         // Create handler that provides incompatible version 2.0 in the context
@@ -1012,7 +1011,6 @@ public void testVersionNotSupportedErrorOnSendStreamingMessage() throws Exceptio
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         // Create handler that provides incompatible version 2.0 in the context
@@ -1058,7 +1056,6 @@ public void testCompatibleVersionSuccess() throws Exception {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         // Create handler that provides compatible version 1.1 in the context
@@ -1110,7 +1107,6 @@ public void testNoVersionDefaultsToCurrentVersionSuccess() throws Exception {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         // Create handler that provides null version (should default to 1.0)
diff --git a/transport/jsonrpc/src/test/java/io/a2a/transport/jsonrpc/handler/JSONRPCHandlerTest.java b/transport/jsonrpc/src/test/java/io/a2a/transport/jsonrpc/handler/JSONRPCHandlerTest.java
index c8e69f43..a55233ad 100644
--- a/transport/jsonrpc/src/test/java/io/a2a/transport/jsonrpc/handler/JSONRPCHandlerTest.java
+++ b/transport/jsonrpc/src/test/java/io/a2a/transport/jsonrpc/handler/JSONRPCHandlerTest.java
@@ -1781,7 +1781,6 @@ public void testVersionNotSupportedErrorOnMessageSend() {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         JSONRPCHandler handler = new JSONRPCHandler(agentCard, requestHandler, internalExecutor);
@@ -1821,7 +1820,6 @@ public void testVersionNotSupportedErrorOnMessageSendStream() throws Exception {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         JSONRPCHandler handler = new JSONRPCHandler(agentCard, requestHandler, internalExecutor);
@@ -1898,7 +1896,6 @@ public void testCompatibleVersionSuccess() {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         JSONRPCHandler handler = new JSONRPCHandler(agentCard, requestHandler, internalExecutor);
@@ -1942,7 +1939,6 @@ public void testNoVersionDefaultsToCurrentVersionSuccess() {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         JSONRPCHandler handler = new JSONRPCHandler(agentCard, requestHandler, internalExecutor);
diff --git a/transport/rest/src/test/java/io/a2a/transport/rest/handler/RestHandlerTest.java b/transport/rest/src/test/java/io/a2a/transport/rest/handler/RestHandlerTest.java
index df2a5e7a..7a151cfc 100644
--- a/transport/rest/src/test/java/io/a2a/transport/rest/handler/RestHandlerTest.java
+++ b/transport/rest/src/test/java/io/a2a/transport/rest/handler/RestHandlerTest.java
@@ -628,7 +628,6 @@ public void testVersionNotSupportedErrorOnSendMessage() {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         RestHandler handler = new RestHandler(agentCard, requestHandler, internalExecutor);
@@ -680,7 +679,6 @@ public void testVersionNotSupportedErrorOnSendStreamingMessage() {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         RestHandler handler = new RestHandler(agentCard, requestHandler, internalExecutor);
@@ -769,7 +767,6 @@ public void testCompatibleVersionSuccess() {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         RestHandler handler = new RestHandler(agentCard, requestHandler, internalExecutor);
@@ -825,7 +822,6 @@ public void testNoVersionDefaultsToCurrentVersionSuccess() {
                 .defaultInputModes(List.of("text"))
                 .defaultOutputModes(List.of("text"))
                 .skills(List.of())
-                .protocolVersion("1.0")
                 .build();
 
         RestHandler handler = new RestHandler(agentCard, requestHandler, internalExecutor);