diff --git a/activitysim/core/skim_dictionary.py b/activitysim/core/skim_dictionary.py
index 587eaab89e..ba23b85dce 100644
--- a/activitysim/core/skim_dictionary.py
+++ b/activitysim/core/skim_dictionary.py
@@ -123,8 +123,13 @@ def map(self, zone_ids):
         if self.offset_series is not None:
             assert(self.offset_int is None)
             assert isinstance(self.offset_series, pd.Series)
-            # FIXME - faster to use series.map if zone_ids is a series?
-            offsets = quick_loc_series(zone_ids, self.offset_series).fillna(NOT_IN_SKIM_ZONE_ID).astype(int)
+
+            # FIXME - turns out it is faster to use series.map if zone_ids is a series
+            # offsets = quick_loc_series(zone_ids, self.offset_series).fillna(NOT_IN_SKIM_ZONE_ID).astype(int)
+
+            if isinstance(zone_ids, np.ndarray):
+                zone_ids = pd.Series(zone_ids)
+            offsets = zone_ids.map(self.offset_series, na_action='ignore').fillna(NOT_IN_SKIM_ZONE_ID).astype(int)
 
         elif self.offset_int:
             assert (self.offset_series is None)
diff --git a/activitysim/core/util.py b/activitysim/core/util.py
index 0000051df7..1351023f37 100644
--- a/activitysim/core/util.py
+++ b/activitysim/core/util.py
@@ -243,32 +243,13 @@ def quick_loc_df(loc_list, target_df, attribute=None):
     -------
         pandas.DataFrame or, if attribbute specified, pandas.Series
     """
-
-    left_on = "left"
-
-    if isinstance(loc_list, pd.Int64Index):
-        left_df = pd.DataFrame({left_on: loc_list.values})
-    elif isinstance(loc_list, pd.Series):
-        left_df = loc_list.to_frame(name=left_on)
-    elif isinstance(loc_list, np.ndarray):
-        left_df = pd.DataFrame({left_on: loc_list})
-    else:
-        raise RuntimeError("quick_loc_df loc_list of unexpected type %s" % type(loc_list))
-
     if attribute:
         target_df = target_df[[attribute]]
 
-    df = pd.merge(left_df,
-                  target_df,
-                  left_on=left_on,
-                  right_index=True,
-                  how="left").set_index(left_on)
+    df = target_df.reindex(loc_list)
 
     df.index.name = target_df.index.name
 
-    # regression test
-    # assert df.equals(target_df.loc[loc_list])
-
     if attribute:
         # return series
         return df[attribute]