diff --git a/contrib/build-wine/build-electrum-git.sh b/contrib/build-wine/build-electrum-git.sh
index 991f5fec1..1dbe1511d 100755
--- a/contrib/build-wine/build-electrum-git.sh
+++ b/contrib/build-wine/build-electrum-git.sh
@@ -2,7 +2,7 @@
 
 NAME_ROOT=electrum
 
-export PYTHONDONTWRITEBYTECODE=1
+export PYTHONDONTWRITEBYTECODE=1  # don't create __pycache__/ folders with .pyc files
 
 
 # Let's begin!
diff --git a/contrib/osx/make_osx b/contrib/osx/make_osx
index acae6e42e..05a31758b 100755
--- a/contrib/osx/make_osx
+++ b/contrib/osx/make_osx
@@ -7,6 +7,7 @@ PACKAGE=Electrum
 GIT_REPO=https://github.com/spesmilo/electrum
 
 export GCC_STRIP_BINARIES="1"
+export PYTHONDONTWRITEBYTECODE=1  # don't create __pycache__/ folders with .pyc files
 
 
 . "$(dirname "$0")/../build_tools_util.sh"