diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2b29109..bde0b67 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project (attempts to) adhere to [Semantic Versioning](http://semver.org/).
 
+## [2.5.4] - 2020-03-06
+- Trying to fix a bug related to pandas categories
+
 ## [2.5.3] - 2020-02-27
 ### Fixed
 - More bug fixes related to FastANI
diff --git a/drep/VERSION b/drep/VERSION
index aedc15b..fe16b34 100644
--- a/drep/VERSION
+++ b/drep/VERSION
@@ -1 +1 @@
-2.5.3
+2.5.4
diff --git a/drep/d_cluster.py b/drep/d_cluster.py
index a57fc81..8f6186e 100644
--- a/drep/d_cluster.py
+++ b/drep/d_cluster.py
@@ -596,8 +596,8 @@ def all_vs_all_MASH(Bdb, data_folder, **kwargs):
     uCols = ['genome1','genome2','dist']
     dTypes = {'genome1':'category', 'genome2':'category', 'dist':np.float32}
     Mdb = pd.read_csv(file, names=iniCols, usecols=uCols, dtype=dTypes, sep='\t')
-    Mdb['genome1'] = Mdb['genome1'].apply(_get_genome_name_from_fasta)
-    Mdb['genome2'] = Mdb['genome2'].apply(_get_genome_name_from_fasta)
+    Mdb['genome1'] = Mdb['genome1'].apply(_get_genome_name_from_fasta).astype('category')
+    Mdb['genome2'] = Mdb['genome2'].apply(_get_genome_name_from_fasta).astype('category')
     Mdb['similarity'] = 1 - Mdb['dist']
 
     # Filter out those genomes that are in the MASH folder but shouldn't be in Mdb