diff --git a/stirling-pdf/src/main/java/stirling/software/SPDF/controller/api/security/CertSignController.java b/stirling-pdf/src/main/java/stirling/software/SPDF/controller/api/security/CertSignController.java
index 2b4f90c33..7675355da 100644
--- a/stirling-pdf/src/main/java/stirling/software/SPDF/controller/api/security/CertSignController.java
+++ b/stirling-pdf/src/main/java/stirling/software/SPDF/controller/api/security/CertSignController.java
@@ -65,6 +65,7 @@ import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.multipart.MultipartFile;
 
 import io.github.pixee.security.Filenames;
+import io.micrometer.common.util.StringUtils;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;