diff --git a/schema/common.json b/schema/common.json
index 274fcb55..8276ad4b 100644
--- a/schema/common.json
+++ b/schema/common.json
@@ -128,6 +128,10 @@
         "ConsoleExporter": {
             "type": ["object", "null"],
             "additionalProperties": false
+        },
+        "NonEmptyString": {
+            "type": "string",
+            "minLength": 1
         }
     }
 }
\ No newline at end of file
diff --git a/schema/propagator.json b/schema/propagator.json
index 633572bb..2f6fc59b 100644
--- a/schema/propagator.json
+++ b/schema/propagator.json
@@ -6,7 +6,7 @@
         "composite": {
             "type": "array",
             "items": {
-                "type": ["string"]
+                "$ref": "common.json#/$defs/NonEmptyString"
             }
         }
     },