diff --git a/kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/SSEServerTransport.kt b/kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/SSEServerTransport.kt
index c662464d..1b33f39e 100644
--- a/kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/SSEServerTransport.kt
+++ b/kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/SSEServerTransport.kt
@@ -80,7 +80,7 @@ public class SseServerTransport(private val endpoint: String, private val sessio
 
         val body = try {
             val ct = call.request.contentType()
-            if (ct != ContentType.Application.Json) {
+            if (!ct.match(ContentType.Application.Json)) {
                 error("Unsupported content-type: $ct")
             }