diff --git a/core/test/unit/api/v2/utils/serializers/input/posts_spec.js b/core/test/unit/api/v2/utils/serializers/input/posts_spec.js
index a7ee328bfb..908c9e8ad6 100644
--- a/core/test/unit/api/v2/utils/serializers/input/posts_spec.js
+++ b/core/test/unit/api/v2/utils/serializers/input/posts_spec.js
@@ -448,6 +448,28 @@ describe('Unit: v2/utils/serializers/input/posts', function () {
                 postData.mobiledoc.should.not.equal(mobiledoc);
                 postData.mobiledoc.should.equal('{"version":"0.3.1","atoms":[],"cards":[],"markups":[],"sections":[[1,"p",[[0,[],0,"this is great feature"]]]]}');
             });
+
+            it('preserves html cards in transformed html', function () {
+                const apiConfig = {};
+                const frame = {
+                    options: {
+                        source: 'html'
+                    },
+                    data: {
+                        posts: [
+                            {
+                                id: 'id1',
+                                html: '<p>this is great feature</p>\n<!--kg-card-begin: html--><div class="custom">My Custom HTML</div><!--kg-card-end: html-->\n<p>custom html preserved!</p>',
+                            }
+                        ]
+                    }
+                };
+
+                serializers.input.posts.edit(apiConfig, frame);
+
+                let postData = frame.data.posts[0];
+                postData.mobiledoc.should.equal('{"version":"0.3.1","atoms":[],"cards":[["html",{"html":"<div class=\"custom\">My Custom HTML</div>"}]],"markups":[],"sections":[[1,"p",[[0,[],0,"this is great feature"]]],[10,0],[1,"p",[[0,[],0,"custom html preserved!"]]]]}');
+            });
         });
 
         describe('Ensure relations format', function () {
diff --git a/package.json b/package.json
index b54fe0c98d..45a57da3d7 100644
--- a/package.json
+++ b/package.json
@@ -119,7 +119,7 @@
     "xml": "1.0.1"
   },
   "optionalDependencies": {
-    "@tryghost/html-to-mobiledoc": "0.3.0",
+    "@tryghost/html-to-mobiledoc": "0.4.0",
     "sharp": "0.21.3",
     "sqlite3": "4.0.6"
   },
diff --git a/yarn.lock b/yarn.lock
index 236c7d55de..c320b03856 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -111,13 +111,13 @@
   dependencies:
     lodash-es "^4.17.11"
 
-"@tryghost/html-to-mobiledoc@0.3.0":
-  version "0.3.0"
-  resolved "https://registry.yarnpkg.com/@tryghost/html-to-mobiledoc/-/html-to-mobiledoc-0.3.0.tgz#6985fac775000c0ea96c3a36e3275c68a8b83f7e"
-  integrity sha512-X69oETTdfjSwi99t0tMkRzwNBrNBOV4elhS0kpDuvfQ/zKhuzlRgjvsGIvzX8zG0/NYm1ZlUaOpgBRz6i6P17w==
+"@tryghost/html-to-mobiledoc@0.4.0":
+  version "0.4.0"
+  resolved "https://registry.yarnpkg.com/@tryghost/html-to-mobiledoc/-/html-to-mobiledoc-0.4.0.tgz#2dd7111c10213634bfd39dc00d5171abe0f2a321"
+  integrity sha512-YIBqjfXy2l51/zMpNuHilDkZizxF7WYRkATKqh7uKy2UJs+yeJq9gwQBojAvwDOc8Lmdwj/sJGLlg5jWs9dRCA==
   dependencies:
-    "@tryghost/kg-parser-plugins" "^0.4.1"
-    "@tryghost/mobiledoc-kit" "^0.11.2-ghost.1"
+    "@tryghost/kg-parser-plugins" "^0.5.0"
+    "@tryghost/mobiledoc-kit" "^0.11.2-ghost.3"
     jsdom "14.1.0"
 
 "@tryghost/kg-clean-basic-html@^0.1.1":
@@ -125,10 +125,10 @@
   resolved "https://registry.yarnpkg.com/@tryghost/kg-clean-basic-html/-/kg-clean-basic-html-0.1.1.tgz#a065a5771c29af47d7e681fc6ac2db445b839daf"
   integrity sha512-pHszGBQMo6r9YTg9VTDJsn0+i+rRNTs09dAMI8ZbD11AP0ten5XJxIqLQuDJJwIrchZ91J2rl+LMgnQo1yIyNw==
 
-"@tryghost/kg-parser-plugins@^0.4.1":
-  version "0.4.1"
-  resolved "https://registry.yarnpkg.com/@tryghost/kg-parser-plugins/-/kg-parser-plugins-0.4.1.tgz#d504976e2ec9eb5fdfdca19fecf3a03a94aebf08"
-  integrity sha512-J1Gn91hIG2pxgwWymPnKcsWsF4BB08tR+Qdg9uqyE5JGwIGGQdNTxgbXSRaMOcHorlmNKqb0bZlnk2l2d/AAYA==
+"@tryghost/kg-parser-plugins@^0.5.0":
+  version "0.5.0"
+  resolved "https://registry.yarnpkg.com/@tryghost/kg-parser-plugins/-/kg-parser-plugins-0.5.0.tgz#def06ea586e1a075105531f289d49f9c91996203"
+  integrity sha512-0Vq0lfSXKkn8mLYb4Wz0VlK7pNtrhoioPQnG8o+/Juu8r4CHtHiLgGqTPWzPntd4wXNnBLAS3SppPE5GRM1Wng==
   dependencies:
     "@tryghost/kg-clean-basic-html" "^0.1.1"
 
@@ -184,10 +184,10 @@
     ghost-ignition "^3.1.0"
     lodash "^4.17.11"
 
-"@tryghost/mobiledoc-kit@^0.11.2-ghost.1":
-  version "0.11.2-ghost.1"
-  resolved "https://registry.yarnpkg.com/@tryghost/mobiledoc-kit/-/mobiledoc-kit-0.11.2-ghost.1.tgz#7088eb9eef06b4ccdd6c221613f20d01b106f939"
-  integrity sha512-oc5zAQiEzq0oSUb3NpAXHvfcQ+FOjzQ+1sRNv2QwSJ+JftanpdFvgmc9BwX8dZAlHA/NOnrIeTW1Q2Ip9Nm2Ag==
+"@tryghost/mobiledoc-kit@^0.11.2-ghost.3":
+  version "0.11.2-ghost.3"
+  resolved "https://registry.yarnpkg.com/@tryghost/mobiledoc-kit/-/mobiledoc-kit-0.11.2-ghost.3.tgz#15d5ad0ce0b2c4322ba5e2fc87f641dcb387e8ff"
+  integrity sha512-R07zG7vLViPt2SmJSQXPTdgakfsra9GcP+O2saa0SYzfdTE/+3+hMo0PgJSwcyCx898mJmQv6L1lgu7N7qjihw==
   dependencies:
     mobiledoc-dom-renderer "0.6.5"
     mobiledoc-text-renderer "0.3.2"