diff --git a/src/components/views/elements/MessageEditor.js b/src/components/views/elements/MessageEditor.js
index cf306d80bb..f51348ce04 100644
--- a/src/components/views/elements/MessageEditor.js
+++ b/src/components/views/elements/MessageEditor.js
@@ -280,6 +280,7 @@ export default class MessageEditor extends React.Component {
     }
 
     componentWillUnmount() {
+        this._editorRef.removeEventListener("input", this._onInput, true);
         const sel = document.getSelection();
         const {caret} = getCaretOffsetAndText(this._editorRef, sel);
         const parts = this.model.serializeParts();
@@ -292,6 +293,9 @@ export default class MessageEditor extends React.Component {
         this._updateEditorState();
         // initial caret position
         this._initializeCaret();
+        // attach input listener by hand so React doesn't proxy the events,
+        // as the proxied event doesn't support inputType, which we need.
+        this._editorRef.addEventListener("input", this._onInput, true);
         this._editorRef.focus();
     }
 
@@ -359,7 +363,6 @@ export default class MessageEditor extends React.Component {
                     className="mx_MessageEditor_editor"
                     contentEditable="true"
                     tabIndex="1"
-                    onInput={this._onInput}
                     onKeyDown={this._onKeyDown}
                     ref={ref => this._editorRef = ref}
                     aria-label={_t("Edit message")}
diff --git a/src/editor/model.js b/src/editor/model.js
index 1080df67ba..530aeef0b2 100644
--- a/src/editor/model.js
+++ b/src/editor/model.js
@@ -97,24 +97,26 @@ export default class EditorModel {
         if (diff.removed) {
             removedOffsetDecrease = this.removeText(position, diff.removed.length);
         }
+        const canOpenAutoComplete = inputType !== "insertFromPaste" && inputType !== "insertFromDrop";
         let addedLen = 0;
         if (diff.added) {
-            addedLen = this._addText(position, diff.added);
+            // these shouldn't trigger auto-complete, you just want to append a piece of text
+            addedLen = this._addText(position, diff.added, {validate: canOpenAutoComplete});
         }
         this._mergeAdjacentParts();
         const caretOffset = diff.at - removedOffsetDecrease + addedLen;
         const newPosition = this.positionForOffset(caretOffset, true);
-        this._setActivePart(newPosition);
+        this._setActivePart(newPosition, canOpenAutoComplete);
         this._updateCallback(newPosition);
     }
 
-    _setActivePart(pos) {
+    _setActivePart(pos, canOpenAutoComplete) {
         const {index} = pos;
         const part = this._parts[index];
         if (part) {
             if (index !== this._activePartIdx) {
                 this._activePartIdx = index;
-                if (this._activePartIdx !== this._autoCompletePartIdx) {
+                if (canOpenAutoComplete && this._activePartIdx !== this._autoCompletePartIdx) {
                     // else try to create one
                     const ac = part.createAutoComplete(this._onAutoComplete);
                     if (ac) {
@@ -217,17 +219,22 @@ export default class EditorModel {
      * inserts `str` into the model at `pos`.
      * @param {Object} pos
      * @param {string} str
+     * @param {Object} options
+     * @param {bool} options.validate Whether characters will be validated by the part.
+     *                                Validating allows the inserted text to be parsed according to the part rules.
      * @return {Number} how far from position (in characters) the insertion ended.
      * This can be more than the length of `str` when crossing non-editable parts, which are skipped.
      */
-    _addText(pos, str) {
+    _addText(pos, str, {validate=true}) {
         let {index} = pos;
         const {offset} = pos;
         let addLen = str.length;
         const part = this._parts[index];
         if (part) {
             if (part.canEdit) {
-                if (part.insertAll(offset, str)) {
+                if (validate && part.validateAndInsert(offset, str)) {
+                    str = null;
+                } else if (!validate && part.insert(offset, str)) {
                     str = null;
                 } else {
                     const splitPart = part.split(offset);
@@ -240,10 +247,19 @@ export default class EditorModel {
                 addLen += part.text.length - offset;
                 index += 1;
             }
+        } else if (index < 0) {
+            // if position was not found (index: -1, as happens for empty editor)
+            // reset it to insert as first part
+            index = 0;
         }
         while (str) {
             const newPart = this._partCreator.createPartForInput(str);
-            str = newPart.appendUntilRejected(str);
+            if (validate) {
+                str = newPart.appendUntilRejected(str);
+            } else {
+                newPart.insert(0, str);
+                str = null;
+            }
             this._insertPart(index, newPart);
             index += 1;
         }
diff --git a/src/editor/parts.js b/src/editor/parts.js
index dc2c1e69a2..572a861024 100644
--- a/src/editor/parts.js
+++ b/src/editor/parts.js
@@ -69,7 +69,7 @@ class BasePart {
 
     // inserts str at offset if all the characters in str were accepted, otherwise don't do anything
     // return whether the str was accepted or not.
-    insertAll(offset, str) {
+    validateAndInsert(offset, str) {
         for (let i = 0; i < str.length; ++i) {
             const chr = str.charAt(i);
             if (!this.acceptsInsertion(chr)) {
@@ -82,6 +82,16 @@ class BasePart {
         return true;
     }
 
+    insert(offset, str) {
+        if (this.canEdit) {
+            const beforeInsert = this._text.substr(0, offset);
+            const afterInsert = this._text.substr(offset);
+            this._text = beforeInsert + str + afterInsert;
+            return true;
+        }
+        return false;
+    }
+
     createAutoComplete() {}
 
     trim(len) {