diff --git a/.changeset/stupid-hats-poke.md b/.changeset/stupid-hats-poke.md
new file mode 100644
index 0000000..dda0377
--- /dev/null
+++ b/.changeset/stupid-hats-poke.md
@@ -0,0 +1,5 @@
+---
+"server-sdk-kotlin": patch
+---
+
+Add missing headers for SipService call
diff --git a/src/main/kotlin/io/livekit/server/SipService.kt b/src/main/kotlin/io/livekit/server/SipService.kt
index af2b97c..a44c948 100644
--- a/src/main/kotlin/io/livekit/server/SipService.kt
+++ b/src/main/kotlin/io/livekit/server/SipService.kt
@@ -84,6 +84,7 @@ interface SipService {
         @Header("Authorization") authorization: String
     ): Call<LivekitSip.SIPDispatchRuleInfo>
 
+    @Headers("Content-Type: application/protobuf")
     @POST("/twirp/livekit.SIP/UpdateSIPDispatchRule")
     fun updateSipDispatchRule(
         @Body request: LivekitSip.UpdateSIPDispatchRuleRequest,