diff --git a/src/wrf/util.py b/src/wrf/util.py
index 40229c7..99ef9ae 100644
--- a/src/wrf/util.py
+++ b/src/wrf/util.py
@@ -9,6 +9,7 @@
 from types import GeneratorType
 import datetime as dt
 from inspect import getmodule
+from netCDF4 import Dataset
 
 try:
     from inspect import signature
@@ -134,7 +135,14 @@ def is_multi_file(wrfin):
         is a single NetCDF file object.
 
     """
-    return (isinstance(wrfin, Iterable) and not isstr(wrfin))
+    if isinstance(wrfin, Dataset):
+        is_iterable = False
+    elif isinstance(wrfin, Iterable):
+        is_iterable = True
+    else:
+        is_iterable = False
+
+    return (is_iterable and not isstr(wrfin))
 
 
 def has_time_coord(wrfnc):