diff --git a/debian/patches/series b/debian/patches/series
index c3d0c81a..0e8c7b89 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -26,3 +26,4 @@ build-fix-pie.patch
 build-fix-excludes.patch
 build-system-revamp.patch
 fix-build-with-newer-openssl.patch
+sipwise/0020-TT-9521-fix-200OK-without-SPD.patch
diff --git a/debian/patches/sipwise/0020-TT-9521-fix-200OK-without-SPD.patch b/debian/patches/sipwise/0020-TT-9521-fix-200OK-without-SPD.patch
new file mode 100644
index 00000000..3440d718
--- /dev/null
+++ b/debian/patches/sipwise/0020-TT-9521-fix-200OK-without-SPD.patch
@@ -0,0 +1,14 @@
+Index: sems/core/AmOfferAnswer.cpp
+===================================================================
+--- sems.orig/core/AmOfferAnswer.cpp
++++ sems/core/AmOfferAnswer.cpp
+@@ -392,6 +392,9 @@ int AmOfferAnswer::onReplyOut(AmSipReply
+       if (reply.code == 183 && reply.cseq_method == SIP_METH_INVITE) {
+         // just ignore if no SDP is generated (required for B2B)
+       }
++      else if (reply.code == 200 && reply.cseq_method == SIP_METH_INVITE && state == OA_Completed) {
++        // just ignore if no SDP is generated (required for B2B)
++      }
+       else return -1;
+     }
+     else {