diff --git a/modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/processors/ExternalRefProcessor.java b/modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/processors/ExternalRefProcessor.java
index 6edc05d5cc..8be30f63f2 100644
--- a/modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/processors/ExternalRefProcessor.java
+++ b/modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/processors/ExternalRefProcessor.java
@@ -79,7 +79,14 @@ private String finalNameRec(Map<String, Schema> schemas, String possiblyConflict
         return tryName;
     }
 
+    private String normalizeRelativeRef(String $ref, RefFormat refFormat) {
+        if (refFormat == RefFormat.RELATIVE && !$ref.startsWith("./")) {
+            return "./" + $ref;
+        }
+        return $ref;
+    }
     public String processRefToExternalSchema(String $ref, RefFormat refFormat) {
+        $ref = normalizeRelativeRef($ref, refFormat);
         String renamedRef = cache.getRenamedRef($ref);
         if(renamedRef != null) {
             return renamedRef;