diff --git a/src/Type/YText.js b/src/Type/YText.js
index 16dd9318..959b92fe 100644
--- a/src/Type/YText.js
+++ b/src/Type/YText.js
@@ -24,6 +24,9 @@ export default class YText extends YArray {
     return strBuilder.join('')
   }
   insert (pos, text) {
+    if (text.length <= 0) {
+      return
+    }
     this._transact(y => {
       let left = null
       let right = this._start
diff --git a/src/Util/ID.js b/src/Util/ID.js
index 3c3e8235..fc261340 100644
--- a/src/Util/ID.js
+++ b/src/Util/ID.js
@@ -11,6 +11,10 @@ export default class ID {
     return id !== null && id.user === this.user && id.clock === this.clock
   }
   lessThan (id) {
-    return this.user < id.user || (this.user === id.user && this.clock < id.clock)
+    if (id.constructor === ID) {
+      return this.user < id.user || (this.user === id.user && this.clock < id.clock)
+    } else {
+      return false
+    }
   }
 }
diff --git a/src/Util/RootID.js b/src/Util/RootID.js
index 0968dced..1e4610f9 100644
--- a/src/Util/RootID.js
+++ b/src/Util/RootID.js
@@ -12,6 +12,10 @@ export default class RootID {
     return id !== null && id.user === this.user && id.name === this.name && id.type === this.type
   }
   lessThan (id) {
-    return this.user < id.user || (this.user === id.user && (this.name < id.name || (this.name === id.name && this.type < id.type)))
+    if (id.constructor === RootID) {
+      return this.user < id.user || (this.user === id.user && (this.name < id.name || (this.name === id.name && this.type < id.type)))
+    } else {
+      return true
+    }
   }
 }