diff --git a/Dockerfile b/Dockerfile
index 135241e..d5c7efa 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,5 +14,5 @@ COPY mapq0_vcf_filter.sh /usr/bin/mapq0_vcf_filter.sh
 COPY add_mq0_and_filter.py /usr/bin/add_mq0_and_filter.py
 RUN chmod +x /usr/bin/mapq0_vcf_filter.sh /usr/bin/add_mq0_and_filter.py
 RUN pip3 install cython==0.29.19
-RUN pip3 install pysam==0.16.0.1
+RUN pip3 install pysam==0.15.4
 RUN pip3 install pysamstats==1.1.2