diff --git a/.gitignore b/.gitignore
index 7ba75f1..46a92ea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -79,3 +79,4 @@ Makefile.in
 /src/matrix-event-call-candidates.c
 /src/matrix-event-call-answer.c
 /src/matrix-event-call-hangup.c
+/src/matrix-event-call-base.c
diff --git a/src/Makefile.am b/src/Makefile.am
index e233bad..6fdf4b1 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -45,6 +45,7 @@ libmatrix_glib_0_0_la_VALA_SOURCES = \
 	matrix-event-room-guest-access.vala \
 	matrix-event-room-redaction.vala \
 	matrix-event-room-third-party-invite.vala \
+	matrix-event-call-base.vala \
 	matrix-event-call-invite.vala \
 	matrix-event-call-candidates.vala \
 	matrix-event-call-answer.vala \
diff --git a/src/matrix-event-call-answer.vala b/src/matrix-event-call-answer.vala
index 93289ac..ca81bee 100644
--- a/src/matrix-event-call-answer.vala
+++ b/src/matrix-event-call-answer.vala
@@ -19,12 +19,7 @@
 /**
  * This event is sent by the callee when they wish to answer the call.
  */
-public class Matrix.Event.CallAnswer : Matrix.Event.Room {
-    /**
-     * The ID of the call this event relates to.
-     */
-    public string? call_id { get; set; default = null; }
-
+public class Matrix.Event.CallAnswer : Matrix.Event.Call {
     /**
      * The type of session description.
      */
@@ -35,11 +30,6 @@ public class Matrix.Event.CallAnswer : Matrix.Event.Room {
      */
     public string? answer_sdp { get; set; default = null; }
 
-    /**
-     * The version of the VoIP specification this messages adheres to.
-     */
-    public int? version { get; set; default = null; }
-
     protected override void
     from_json(Json.Node json_data)
         throws Matrix.Error
@@ -48,12 +38,6 @@ public class Matrix.Event.CallAnswer : Matrix.Event.Room {
             .get_member("content").get_object();
         Json.Node? node;
 
-        if ((node = content_root.get_member("call_id")) != null) {
-            _call_id = node.get_string();
-        } else {
-            warning("content.call_id is missing from a m.call.answer event");
-        }
-
         if ((node = content_root.get_member("answer")) != null) {
             var answer_root = node.get_object();
 
@@ -79,12 +63,6 @@ public class Matrix.Event.CallAnswer : Matrix.Event.Room {
             }
         }
 
-        if ((node = content_root.get_member("version")) != null) {
-            _version = (int)node.get_int();
-        } else {
-            warning("content.version is missing from a m.call.answer event");
-        }
-
         base.from_json(json_data);
     }
 
@@ -92,16 +70,6 @@ public class Matrix.Event.CallAnswer : Matrix.Event.Room {
     to_json(Json.Node json_data)
         throws Matrix.Error
     {
-        if (_version == null) {
-            throw new Matrix.Error.INCOMPLETE(
-                    "Won't generate a m.call.answer event without version");
-        }
-
-        if (_call_id == null) {
-            throw new Matrix.Error.INCOMPLETE(
-                    "Won't generate a m.call.answer event without call_id");
-        }
-
         if (_answer_type == null) {
             throw new Matrix.Error.INCOMPLETE(
                     "Won't generate a m.call.answer event without answer.type");
@@ -115,9 +83,6 @@ public class Matrix.Event.CallAnswer : Matrix.Event.Room {
         var content_root = json_data.get_object()
             .get_member("content").get_object();
 
-        content_root.set_string_member("call_id", _call_id);
-        content_root.set_int_member("version", _version);
-
         var answer_root = new Json.Object();
         var answer_node = new Json.Node(Json.NodeType.OBJECT);
         answer_node.set_object(answer_root);
diff --git a/src/matrix-event-call-base.vala b/src/matrix-event-call-base.vala
new file mode 100644
index 0000000..941148b
--- /dev/null
+++ b/src/matrix-event-call-base.vala
@@ -0,0 +1,78 @@
+/*
+ * This file is part of matrix-glib-sdk
+ *
+ * matrix-glib-sdk is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * matrix-glib-sdk is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with matrix-glib-sdk. If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Base class for m.call.* events.
+ */
+public abstract class Matrix.Event.Call : Matrix.Event.Room {
+    /**
+     * The ID of the call this event relates to.
+     */
+    public string? call_id { get; set; default = null; }
+
+    /**
+     * The version of the VoIP specification this message adheres to.
+     */
+    public int? version { get; set; default = null; }
+
+    protected override void
+    from_json(Json.Node json_data)
+        throws Matrix.Error
+    {
+        var content_root = json_data.get_object()
+            .get_member("content").get_object();
+        Json.Node? node;
+
+        if ((node = content_root.get_member("call_id")) != null) {
+            _call_id = node.get_string();
+        } else {
+            warning("content.call_id is missing from a m.call.hangup event");
+        }
+
+        if ((node = content_root.get_member("version")) != null) {
+            _version = (int)node.get_int();
+        } else {
+            warning("content.version is missing from a m.call.hangup event");
+        }
+
+        base.from_json(json_data);
+    }
+
+    protected override void
+    to_json(Json.Node json_data)
+        throws Matrix.Error
+    {
+        if (_call_id == null) {
+            throw new Matrix.Error.INCOMPLETE(
+                    "Won't generate a m.call.hangup event without call_id");
+        }
+
+        if (_version == null) {
+            throw new Matrix.Error.INCOMPLETE(
+                    "Won't generate a m.call.hangup event without version");
+        }
+
+        var content_root = json_data.get_object()
+            .get_member("content").get_object();
+
+        content_root.set_string_member("call_id", _call_id);
+        content_root.set_int_member("version", version);
+
+        base.to_json(json_data);
+    }
+}
diff --git a/src/matrix-event-call-candidates.vala b/src/matrix-event-call-candidates.vala
index 695a5f0..a94c28c 100644
--- a/src/matrix-event-call-candidates.vala
+++ b/src/matrix-event-call-candidates.vala
@@ -21,7 +21,7 @@
  * callee after answering. Its purpose is to give the other party
  * additional ICE candidates to try using to communicate.
  */
-public class Matrix.Event.CallCandidates : Matrix.Event.Room {
+public class Matrix.Event.CallCandidates : Matrix.Event.Call {
     public struct Candidate {
         string? sdp_mid;     /// The SDP media type this candidate is
                              /// intended for.
@@ -30,11 +30,6 @@ public class Matrix.Event.CallCandidates : Matrix.Event.Room {
         string? candidate;   /// The SDP 'a' line of the candidate.
     }
 
-    /**
-     * The ID of the call this event relates to.
-     */
-    public string? call_id { get; set; default = null; }
-
     /**
      * The list of candidates.
      */
@@ -50,11 +45,6 @@ public class Matrix.Event.CallCandidates : Matrix.Event.Room {
         default = null;
     }
 
-    /**
-     * The version of the VoIP specification this messages adheres to.
-     */
-    public int? version { get; set; default = null; }
-
     private List<Candidate?>? _candidates;
 
     protected override void
@@ -65,12 +55,6 @@ public class Matrix.Event.CallCandidates : Matrix.Event.Room {
             .get_member("content").get_object();
         Json.Node? node;
 
-        if ((node = content_root.get_member("call_id")) != null) {
-            _call_id = node.get_string();
-        } else {
-            warning("content.call_id is missing from a m.call.candidates event");
-        }
-
         if ((node = content_root.get_member("candidates")) != null) {
             node.get_array().foreach_element((ary, idx, cand_node) => {
                     var cand_root = cand_node.get_object();
@@ -100,12 +84,6 @@ public class Matrix.Event.CallCandidates : Matrix.Event.Room {
             warning("content.candidates is missing from a m.call.candidates event");
         }
 
-        if ((node = content_root.get_member("version")) != null) {
-            _version = (int)node.get_int();
-        } else {
-            warning("content.version is missing from a m.call.candidates event");
-        }
-
         base.from_json(json_data);
     }
 
@@ -113,16 +91,6 @@ public class Matrix.Event.CallCandidates : Matrix.Event.Room {
     to_json(Json.Node json_data)
         throws Matrix.Error
     {
-        if (_call_id == null) {
-            throw new Matrix.Error.INCOMPLETE(
-                    "Won't generate a m.call.candidates event without call_id");
-        }
-
-        if (_version == null) {
-            throw new Matrix.Error.INCOMPLETE(
-                    "Won't generate a m.call.candidates event without version");
-        }
-
         if ((_candidates == null) || (_candidates.length() < 1)) {
             throw new Matrix.Error.INCOMPLETE(
                     "Won't generate a m.call.candidates event without candidates");
@@ -131,9 +99,6 @@ public class Matrix.Event.CallCandidates : Matrix.Event.Room {
         var content_root = json_data.get_object()
             .get_member("content").get_object();
 
-        content_root.set_string_member("call_id", _call_id);
-        content_root.set_int_member("version", _version);
-
         var cands = new Json.Array();
 
         foreach (var entry in _candidates) {
diff --git a/src/matrix-event-call-hangup.vala b/src/matrix-event-call-hangup.vala
index bb828d6..9b099fb 100644
--- a/src/matrix-event-call-hangup.vala
+++ b/src/matrix-event-call-hangup.vala
@@ -21,37 +21,11 @@
  * can be sent either once the call has has been established or before
  * to abort the call.
  */
-public class Matrix.Event.CallHangup : Matrix.Event.Room {
-    /**
-     * The ID of the call this event relates to.
-     */
-    public string? call_id { get; set; default = null; }
-
-    /**
-     * The version of the VoIP specification this message adheres to.
-     */
-    public int? version { get; set; default = null; }
-
+public class Matrix.Event.CallHangup : Matrix.Event.Call {
     protected override void
     from_json(Json.Node json_data)
         throws Matrix.Error
     {
-        var content_root = json_data.get_object()
-            .get_member("content").get_object();
-        Json.Node? node;
-
-        if ((node = content_root.get_member("call_id")) != null) {
-            _call_id = node.get_string();
-        } else {
-            warning("content.call_id is missing from a m.call.hangup event");
-        }
-
-        if ((node = content_root.get_member("version")) != null) {
-            _version = (int)node.get_int();
-        } else {
-            warning("content.version is missing from a m.call.hangup event");
-        }
-
         base.from_json(json_data);
     }
 
@@ -59,22 +33,6 @@ public class Matrix.Event.CallHangup : Matrix.Event.Room {
     to_json(Json.Node json_data)
         throws Matrix.Error
     {
-        if (_call_id == null) {
-            throw new Matrix.Error.INCOMPLETE(
-                    "Won't generate a m.call.hangup event without call_id");
-        }
-
-        if (_version == null) {
-            throw new Matrix.Error.INCOMPLETE(
-                    "Won't generate a m.call.hangup event without version");
-        }
-
-        var content_root = json_data.get_object()
-            .get_member("content").get_object();
-
-        content_root.set_string_member("call_id", _call_id);
-        content_root.set_int_member("version", version);
-
         base.to_json(json_data);
     }
 }
diff --git a/src/matrix-event-call-invite.vala b/src/matrix-event-call-invite.vala
index 7e1dfc1..78afc6a 100644
--- a/src/matrix-event-call-invite.vala
+++ b/src/matrix-event-call-invite.vala
@@ -20,12 +20,7 @@
  * This event is sent by the caller when they wish to establish a
  * call.
  */
-public class Matrix.Event.CallInvite : Matrix.Event.Room {
-    /**
-     * A unique identifer for the call.
-     */
-    public string? call_id { get; set; default = null;}
-
+public class Matrix.Event.CallInvite : Matrix.Event.Call {
     /**
      * The type of session description.
      */
@@ -35,11 +30,6 @@ public class Matrix.Event.CallInvite : Matrix.Event.Room {
      */
     public string? sdp { get; set; default = null; }
 
-    /**
-     * The version of the VoIP specification this message adheres to.
-     */
-    public int? version { get; set; default = null; }
-
     /**
      * The time in milliseconds that the invite is valid for. Once the
      * invite age exceeds this value, clients should discard it. They
@@ -56,12 +46,6 @@ public class Matrix.Event.CallInvite : Matrix.Event.Room {
             .get_member("content").get_object();
         Json.Node? node;
 
-        if ((node = content_root.get_member("call_id")) != null) {
-            _call_id = node.get_string();
-        } else {
-            warning("content.call_id is missing from a m.call.invite event");
-        }
-
         if ((node = content_root.get_member("offer")) != null) {
             var offer_node = node.get_object();
 
@@ -87,12 +71,6 @@ public class Matrix.Event.CallInvite : Matrix.Event.Room {
             }
         }
 
-        if ((node = content_root.get_member("version")) != null) {
-            _version = (int)node.get_int();
-        } else {
-            warning("content.version is missing from a m.call.invite event");
-        }
-
         if ((node = content_root.get_member("lifetime")) != null) {
             _lifetime = (int)node.get_int();
         } else {
@@ -111,16 +89,11 @@ public class Matrix.Event.CallInvite : Matrix.Event.Room {
                     "Won't generate a m.call.invite without offer.type");
         }
 
-        if (_offer_sdp == null) {
+        if (_sdp == null) {
             throw new Matrix.Error.INCOMPLETE(
                     "Won't generate a m.call.invite without offer.sdp");
         }
 
-        if (_version == null) {
-            throw new Matrix.Error.INCOMPLETE(
-                    "Won't generate a m.call.invite without version");
-        }
-
         if (_lifetime == null) {
             throw new Matrix.Error.INCOMPLETE(
                     "Won't generate a m.call.invite without lifetime");
@@ -129,8 +102,6 @@ public class Matrix.Event.CallInvite : Matrix.Event.Room {
         var content_root = json_data.get_object()
             .get_member("content").get_object();
 
-        content_root.set_string_member("call_id", _call_id);
-        content_root.set_int_member("version", _version);
         content_root.set_int_member("lifetime", _lifetime);
 
         var offer_root = new Json.Object();
@@ -141,7 +112,7 @@ public class Matrix.Event.CallInvite : Matrix.Event.Room {
                 "type",
                 _g_enum_value_to_nick(typeof(CallOfferType),
                                       _offer_type));
-        offer_root.set_string_member("sdp", _offer_sdp);
+        offer_root.set_string_member("sdp", _sdp);
 
         content_root.set_member("offer", offer_node);