diff --git a/src/main/java/org/hbp/mip/controllers/ArticlesApi.java b/src/main/java/org/hbp/mip/controllers/ArticlesApi.java
index 4e22f7b5b3d89ab5ffb5518756e2c8b1717820a1..c3de97577e77150b61e97828f2598652930dce5e 100644
--- a/src/main/java/org/hbp/mip/controllers/ArticlesApi.java
+++ b/src/main/java/org/hbp/mip/controllers/ArticlesApi.java
@@ -134,7 +134,7 @@ public class ArticlesApi {
             } catch (IOException e) {
                 e.printStackTrace();
             }
-            String slug = slg != null ? slg.slugify(article.getTitle()) : null;
+            String slug = slg != null ? slg.slugify(article.getTitle()) : "";
 
             i = 0;
             do {
diff --git a/src/main/java/org/hbp/mip/controllers/ModelsApi.java b/src/main/java/org/hbp/mip/controllers/ModelsApi.java
index 3a9393fa244aa98edcbdacd436a6997a2a6b074f..42c130cdce9ced7f6a15b18972246121d90fdd38 100644
--- a/src/main/java/org/hbp/mip/controllers/ModelsApi.java
+++ b/src/main/java/org/hbp/mip/controllers/ModelsApi.java
@@ -161,12 +161,13 @@ public class ModelsApi {
             } while(count > 0);
 
             Slugify slg = null;
+            String slug = "";
             try {
                 slg = new Slugify();
+                slug = slg.slugify(model.getTitle());
             } catch (IOException e) {
                 e.printStackTrace();
             }
-            String slug = slg != null ? slg.slugify(model.getTitle()) : null;
 
             i = 0;
             do {