diff --git a/blocks/procedures.js b/blocks/procedures.js
index ee4e0958e..49ce8a046 100644
--- a/blocks/procedures.js
+++ b/blocks/procedures.js
@@ -961,32 +961,6 @@ const procedureCallerGetDefMixin = function() {
       return model;
     },
 
-    /**
-     * Creates a procedure definition block with the given name and params,
-     * and returns the procedure model associated with it.
-     * @param {string} name The name of the procedure to create.
-     * @param {string[]} params The names of the parameters to create.
-     * @return {IProcedureModel} The procedure model associated with the new
-     *     procedure definition block.
-     */
-    createDef_(name, params = []) {
-      const xy = this.getRelativeToSurfaceXY();
-      const newName = Procedures.findLegalName(name, this);
-      this.renameProcedure(name, newName);
-
-      const blockDef = {
-        'type': this.defType_,
-        'x': xy.x + config.snapRadius * (this.RTL ? -1 : 1),
-        'y': xy.y + config.snapRadius * 2,
-        'extraState': {
-          'params': params.map((p) => ({'name': p})),
-        },
-        'fields': {'NAME': newName},
-      };
-      return serialization.blocks.append(blockDef, this.getTargetWorkspace_())
-          .getProcedureModel();
-    },
-
     /**
      * @return {Workspace} The main workspace (i.e. not the flyout workspace)
      *     associated with this block.
@@ -1293,7 +1267,6 @@ const procedureCallerOnChangeMixin = {
       // Events not generated by user. Skip handling.
       return;
     }
-    // TODO: Clean this up to call createDef_.
     if (event.type === Events.BLOCK_CREATE &&
         (event.blockId === this.id || event.ids.indexOf(this.id) !== -1)) {
       // Look for the case where a procedure call was created (usually through
@@ -1318,11 +1291,44 @@ const procedureCallerOnChangeMixin = {
     }
   },
 
+  /**
+   * Returns true if the given def block matches the definition of this caller
+   * block.
+   * @param {Block} defBlock The definition block to check against.
+   * @return {boolean} Whether the def block matches or not.
+   */
   defMatches_(defBlock) {
     return defBlock && defBlock.type === this.defType_ &&
         JSON.stringify(defBlock.getVars()) ===
         JSON.stringify(this.paramsFromSerializedState_);
   },
+
+  /**
+   * Creates a procedure definition block with the given name and params,
+   * and returns the procedure model associated with it.
+   * @param {string} name The name of the procedure to create.
+   * @param {string[]} params The names of the parameters to create.
+   * @return {IProcedureModel} The procedure model associated with the new
+   *     procedure definition block.
+   */
+  createDef_(name, params = []) {
+    const xy = this.getRelativeToSurfaceXY();
+    const newName = Procedures.findLegalName(name, this);
+    this.renameProcedure(name, newName);
+
+    const blockDef = {
+      'type': this.defType_,
+      'x': xy.x + config.snapRadius * (this.RTL ? -1 : 1),
+      'y': xy.y + config.snapRadius * 2,
+      'extraState': {
+        'params': params.map((p) => ({'name': p})),
+      },
+      'fields': {'NAME': newName},
+    };
+    return serialization.blocks
+        .append(blockDef, this.getTargetWorkspace_(), {recordUndo: true})
+        .getProcedureModel();
+  },
 };
 Extensions.registerMixin(
     'procedure_caller_onchange_mixin', procedureCallerOnChangeMixin);