diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 6e5260ee7526975bf22b5031bd720a7a323bcf29..0a3092f646872867b0060d79c0fd1c85a40e24f4 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -1003,6 +1003,11 @@ _git_log ()
 	__git_has_doubledash && return
 
 	local cur="${COMP_WORDS[COMP_CWORD]}"
+	local g="$(git rev-parse --git-dir 2>/dev/null)"
+	local merge=""
+	if [ -f $g/MERGE_HEAD ]; then
+		merge="--merge"
+	fi
 	case "$cur" in
 	--pretty=*)
 		__gitcomp "$__git_log_pretty_formats
@@ -1030,7 +1035,7 @@ _git_log ()
 			--decorate
 			--walk-reflogs
 			--parents --children
-			--merge
+			$merge
 			$__git_diff_common_options
 			--pickaxe-all --pickaxe-regex
 			"