diff --git a/types/sdp-transform/index.d.ts b/types/sdp-transform/index.d.ts
index 5136eebb73..57e2731d87 100644
--- a/types/sdp-transform/index.d.ts
+++ b/types/sdp-transform/index.d.ts
@@ -39,6 +39,7 @@ export interface SessionDescription extends SharedDescriptionFields, SessionAttr
         sessionId: string | number;
         sessionVersion: number;
         netType: string;
+        ipVer: number;
         address: string;
     };
     // s=
diff --git a/types/sdp-transform/sdp-transform-tests.ts b/types/sdp-transform/sdp-transform-tests.ts
index 93f3ae5107..2abbf16067 100644
--- a/types/sdp-transform/sdp-transform-tests.ts
+++ b/types/sdp-transform/sdp-transform-tests.ts
@@ -4,15 +4,31 @@ import {
     write,
 } from 'sdp-transform';
 
-const session: SessionDescription = parse('');
-const mediaType: string = session.media[0].type;
-session.media[0].type = 'video';
-const extension: string = session.media[0].ext![0].uri;
-session.media[0].ext![0].uri = 'urn:ietf:params:rtp-hdrext:ssrc-audio-level';
-const codec: string = session.media[0].rtp[0].codec;
-session.media[0].rtp[0].codec = 'opus';
-const config: string = session.media[0].fmtp[0].config;
-session.media[0].fmtp[0].config = 'maxplaybackrate=48000;stereo=1;useinbandfec=1';
-session.media[0].rtcpFb = [{ payload: 96, type: 'ccm', subtype: 'fir' }, { payload: 98, type: 'nack', subtype: 'rpsi' }];
-session.media[0].rtcpFbTrrInt = [{ payload: 96, value: 100 }, { payload: 98, value: 100 }];
-const sdp: string = write(session);
+function test_basic() {
+    const session: SessionDescription = parse('');
+    const mediaType: string = session.media[0].type;
+    session.media[0].type = 'video';
+    const extension: string = session.media[0].ext![0].uri;
+    session.media[0].ext![0].uri = 'urn:ietf:params:rtp-hdrext:ssrc-audio-level';
+    const codec: string = session.media[0].rtp[0].codec;
+    session.media[0].rtp[0].codec = 'opus';
+    const config: string = session.media[0].fmtp[0].config;
+    session.media[0].fmtp[0].config = 'maxplaybackrate=48000;stereo=1;useinbandfec=1';
+    session.media[0].rtcpFb = [{ payload: 96, type: 'ccm', subtype: 'fir' }, { payload: 98, type: 'nack', subtype: 'rpsi' }];
+    session.media[0].rtcpFbTrrInt = [{ payload: 96, value: 100 }, { payload: 98, value: 100 }];
+    const sdp: string = write(session);
+}
+
+function test_origin_fields() {
+    const session: SessionDescription = parse('');
+    session.version = 0;
+    session.origin = {
+        username: 'alice',
+        sessionId: 1591330608,
+        sessionVersion: 1591330609,
+        netType: 'IN',
+        ipVer: 4,
+        address: '127.0.0.1'
+    };
+    const sdp: string = write(session);
+}