diff --git a/src/main/java/com/fasterxml/jackson/databind/type/ResolvedRecursiveType.java b/src/main/java/com/fasterxml/jackson/databind/type/ResolvedRecursiveType.java
index ae0e884e01..4f4984e5af 100644
--- a/src/main/java/com/fasterxml/jackson/databind/type/ResolvedRecursiveType.java
+++ b/src/main/java/com/fasterxml/jackson/databind/type/ResolvedRecursiveType.java
@@ -50,7 +50,7 @@ public StringBuilder getGenericSignature(StringBuilder sb) {
         if (_referencedType != null) {
             return _referencedType.getGenericSignature(sb);
         }
-        return _referencedType.getGenericSignature(sb);
+        return sb.append("?");
     }
 
     @Override
@@ -58,7 +58,7 @@ public StringBuilder getErasedSignature(StringBuilder sb) {
         if (_referencedType != null) {
             return _referencedType.getErasedSignature(sb);
         }
-        return _referencedType.getErasedSignature(sb);
+        return sb;
     }
 
     @Override