diff --git a/requirements.txt b/requirements.txt
index cc64d6b..7f17f9d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-biopython>=1.74.0
+biopython==1.7.7
 networkx>=2.3.0
 fuzzywuzzy
 primers>=0.2.4
\ No newline at end of file