diff --git a/rest_framework/utils/model_meta.py b/rest_framework/utils/model_meta.py
index c1c0f61f0..7a330b1ea 100644
--- a/rest_framework/utils/model_meta.py
+++ b/rest_framework/utils/model_meta.py
@@ -92,7 +92,7 @@ def _get_fields(opts):
 
 
 def _get_to_field(field):
-    return field.to_fields[0] if hasattr(field, 'to_fields') else None
+    return field.to_fields[0] if hasattr(field, 'to_fields') and field.to_fields else None
 
 
 def _get_forward_relationships(opts):