diff --git a/pscore_match/match.py b/pscore_match/match.py
index ff2dc95..006bd0e 100644
--- a/pscore_match/match.py
+++ b/pscore_match/match.py
@@ -397,7 +397,7 @@ def whichMatched(matches, data, show_duplicates = True):
             while j>0:
                 indices.append(i)
                 j -= 1
-        return data.ix[indices]
+        return data.iloc[indices]
     else:
         dat2 = data.copy()
         dat2['weights'] = matches.weights
diff --git a/requirements.txt b/requirements.txt
index 01c1c85..80fab5a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,9 +1,9 @@
-numpy==1.14.1
-scipy==0.17.1
-nose==1.3.7
-coverage==4.2
-coveralls==1.1
-pandas==0.20.1
-statsmodels==0.8.0
-matplotlib==1.5.1
-plotly==2.0.11
\ No newline at end of file
+numpy
+scipy
+nose
+coverage
+coveralls
+pandas
+statsmodels
+matplotlib
+plotly
\ No newline at end of file
diff --git a/setup.py b/setup.py
index f1d95e9..d368330 100755
--- a/setup.py
+++ b/setup.py
@@ -71,6 +71,9 @@ def write_version_py(filename='pscore_match/version.py'):
             'Programming Language :: Python :: 2.7',
             'Programming Language :: Python :: 3.4',
             'Programming Language :: Python :: 3.5',
+            'Programming Language :: Python :: 3.6',
+            'Programming Language :: Python :: 3.7',
+            'Programming Language :: Python :: 3.8',
             'Topic :: Scientific/Engineering',
             'Operating System :: Microsoft :: Windows',
             'Operating System :: POSIX',