diff --git a/test/v2.8/backend.json b/test/v2.8/backend.json
index 2adf797..db0f289 100644
--- a/test/v2.8/backend.json
+++ b/test/v2.8/backend.json
@@ -2,6 +2,14 @@
     "description": "Backend object test",
     "target": "https://www.krakend.io/schema/v2.8/backend.json",
     "tests": [
+        {
+            "description": "Empty host",
+            "data": {
+                "host": [""],
+                "url_pattern": "/__debug/root"
+            },
+            "valid": false
+        },
         {
             "description": "Simple backend declaration with no host",
             "data": {
diff --git a/v2.8/backend.json b/v2.8/backend.json
index 234353a..98ee8ed 100644
--- a/v2.8/backend.json
+++ b/v2.8/backend.json
@@ -84,6 +84,7 @@
       "type": "array",
       "items": {
         "type": "string",
+        "pattern": ".+",
         "minLength": 1
       }
     },
diff --git a/v2.8/krakend.json b/v2.8/krakend.json
index 88ffbb6..0471171 100644
--- a/v2.8/krakend.json
+++ b/v2.8/krakend.json
@@ -1430,6 +1430,7 @@
           "type": "array",
           "items": {
             "type": "string",
+            "pattern": ".+",
             "minLength": 1
           }
         },