diff --git a/git-gui/git-gui.sh b/git-gui/git-gui.sh
index 11048c7a0e94f5..1ed51857e91227 100755
--- a/git-gui/git-gui.sh
+++ b/git-gui/git-gui.sh
@@ -1616,11 +1616,13 @@ proc run_prepare_commit_msg_hook {} {
 	if {[file isfile [gitdir MERGE_MSG]]} {
 		set pcm_source "merge"
 		set fd_mm [open [gitdir MERGE_MSG] r]
+		fconfigure $fd_mm -encoding utf-8
 		puts -nonewline $fd_pcm [read $fd_mm]
 		close $fd_mm
 	} elseif {[file isfile [gitdir SQUASH_MSG]]} {
 		set pcm_source "squash"
 		set fd_sm [open [gitdir SQUASH_MSG] r]
+		fconfigure $fd_sm -encoding utf-8
 		puts -nonewline $fd_pcm [read $fd_sm]
 		close $fd_sm
 	} else {