diff -r 56850f5c73f6 -r cfcbf4bc66f1 client/src/components/CategoriesTooltip.js
--- a/client/src/components/CategoriesTooltip.js	Wed Jul 18 17:32:09 2018 +0200
+++ b/client/src/components/CategoriesTooltip.js	Tue Aug 14 20:34:50 2018 +0200
@@ -1,5 +1,4 @@
 import React, { Component } from 'react';
-import { FormGroup, FormControl, Button } from 'react-bootstrap';
 
 class CategoriesTooltip extends Component {
 
@@ -47,20 +46,22 @@
     return (
       <div className="categories-tooltip">
         <form onSubmit={ this.onSubmit }>
-          <FormGroup className="buttons">
+          <div className="form-group buttons">
           {this.props.categories.map((category) =>
-            <Button
+            <button type="button"
               key={ category.name }
-              bsStyle="primary"
+              className="btn btn-primary"
               style={{ backgroundColor: category.color }}
               active={ this.isCategoryActive(category)  }
-              onClick={ this.onButtonClick.bind(this, category) }>{ category.name }</Button>
+              onClick={ this.onButtonClick.bind(this, category) }>{ category.name }</button>
           )}
-          </FormGroup>
+          </div>
           {this.state.showCommentControl &&
-          <FormGroup>
-            <FormControl inputRef={(ref) => { this.commentControl = ref; }} />
-          </FormGroup>}
+          <div className="form-group">
+            <input className="form-control"
+            // inputRef={(ref) => { this.commentControl = ref; }}
+            ref={(commentControl) => { this.commentControl = commentControl; }}/>
+          </div>}
         </form>
       </div>
     );