diff --git a/.local/bin/btrfs-snap-all b/.local/bin/btrfs-snap-all
index 02f0e4a3..22465af2 100755
--- a/.local/bin/btrfs-snap-all
+++ b/.local/bin/btrfs-snap-all
@@ -9,13 +9,17 @@ Snapshot all Btrfs subvolumes older than 1 day to a read-only '.snapshots/SUBVOL
 Options:
 
   -n: No preview.
+  -g: Run "git gc" on all .git folders.
 
 EOF
 }
 
 OPT_PREVIEW=true
-while getopts ":hn" opt; do
+OPT_GIT_GC=false
+while getopts ":ghn" opt; do
 	case $opt in
+	g)
+		OPT_GIT_GC=true ;;
 	h)
 		usage
 		exit ;;
@@ -29,12 +33,18 @@ done
 
 shift $(($OPTIND - 1))
 
+git_gc() { # $1=rootdir
+	find "$1" -type d -name ".git" -print -exec git --git-dir {} gc \;
+}
+
 snap () { # $1=fs $2=subvol
 	local fs=$1
 	local subvol=$2
+
 	local choice=N
 	local last=$(find "$fs/.snapshots/$subvol" -maxdepth 1 | tail -1)
 
+	$OPT_GIT_GC && git_gc "$fs/subvol"
 	$OPT_PREVIEW && rmirror "$fs/$subvol" "$last"
 
 	echo -n "==> Snapshot '$fs/${subvol}'? (y/N) "