diff --git a/src/frontend/app/signature-book.component.html b/src/frontend/app/signature-book.component.html
index 9b92049b3b140bc5b7258112234c271326d8feb1..5995f8030cfc18b55a869fec265754dffc92e531 100755
--- a/src/frontend/app/signature-book.component.html
+++ b/src/frontend/app/signature-book.component.html
@@ -268,9 +268,9 @@
                             </span>
                             <i *ngIf="loadingSign" class="fa fa-spinner fa-pulse fa-2x fa-fw"></i>
                         </span>
-                        <span *ngIf="signatureBook.attachments[rightSelectedThumbnail].status == 'SIGN' && signatureBook.attachments[rightSelectedThumbnail].idTypist === this.userId; else elseBlock"
+                        <span *ngIf="(signatureBook.attachments[rightSelectedThumbnail].idTypist == this.userId) && (signatureBook.attachments[rightSelectedThumbnail].status === 'SIGN'); else elseBlock"
                             (click)="unsignFile(signatureBook.attachments[rightSelectedThumbnail])"
-                            style="cursor: pointer;color: green;">
+                            style="cursor: pointer;color: green;"> 
                             <i title="{{'lang.unsign' | translate}}" class="fa fa-check fa-2x" aria-hidden="true"></i>
                         </span>
                         <ng-template  #elseBlock>