diff --git a/Python-module/SpatialDE/base.py b/Python-module/SpatialDE/base.py
index cd20bd3..329ba9f 100644
--- a/Python-module/SpatialDE/base.py
+++ b/Python-module/SpatialDE/base.py
@@ -475,7 +475,7 @@ def model_search(X, exp_tab, DE_mll_results, kernel_space=None):
 
     # Retain information from significance testing in the new table
     transfer_columns = ['pval', 'qval', 'max_ll_null']
-    ms_results = ms_results.drop(transfer_columns, 1) \
+    ms_results = ms_results.drop(transfer_columns, axis=1) \
         .merge(DE_mll_results[transfer_columns + ['g']], on='g')
 
     return ms_results