diff --git a/requirements.txt b/requirements.txt
old mode 100755
new mode 100644
index df82c2f..bd160c4
--- a/requirements.txt
+++ b/requirements.txt
@@ -77,7 +77,7 @@ preshed==1.0.0
 progressbar2==3.36.0
 progressbar33==2.4
 prompt-toolkit==1.0.15
-protobuf==3.5.2.post1
+protobuf==3.15.0
 ptyprocess==0.5.2
 py==1.5.4
 pyasn1==0.4.2