diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index e875787710..a61b6ed59a 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -1947,35 +1947,40 @@ __git_diff_difftool_options="--cached --staged
 
 _git_diff ()
 {
-	__git_has_doubledash && return
-
-	case "$cur" in
-	--diff-algorithm=*)
-		__gitcomp "$__git_diff_algorithms" "" "${cur##--diff-algorithm=}"
-		return
-		;;
-	--submodule=*)
-		__gitcomp "$__git_diff_submodule_formats" "" "${cur##--submodule=}"
-		return
-		;;
-	--color-moved=*)
-		__gitcomp "$__git_color_moved_opts" "" "${cur##--color-moved=}"
-		return
-		;;
-	--color-moved-ws=*)
-		__gitcomp "$__git_color_moved_ws_opts" "" "${cur##--color-moved-ws=}"
-		return
-		;;
-	--ws-error-highlight=*)
-		__gitcomp "$__git_ws_error_highlight_opts" "" "${cur##--ws-error-highlight=}"
-		return
-		;;
-	--*)
-		__gitcomp "$__git_diff_difftool_options"
-		return
-		;;
-	esac
-	__git_complete_revlist_file
+	if ! __git_has_doubledash; then
+		case "$cur" in
+		--diff-algorithm=*)
+			__gitcomp "$__git_diff_algorithms" \
+				"" "${cur##--diff-algorithm=}"
+			return
+			;;
+		--submodule=*)
+			__gitcomp "$__git_diff_submodule_formats" \
+				"" "${cur##--submodule=}"
+			return
+			;;
+		--color-moved=*)
+			__gitcomp "$__git_color_moved_opts" \
+				"" "${cur##--color-moved=}"
+			return
+			;;
+		--color-moved-ws=*)
+			__gitcomp "$__git_color_moved_ws_opts" \
+				"" "${cur##--color-moved-ws=}"
+			return
+			;;
+		--ws-error-highlight=*)
+			__gitcomp "$__git_ws_error_highlight_opts" \
+				"" "${cur##--ws-error-highlight=}"
+			return
+			;;
+		--*)
+			__gitcomp "$__git_diff_difftool_options"
+			return
+			;;
+		esac
+		__git_complete_revlist_file
+	fi
 }
 
 __git_mergetools_common="diffuse diffmerge ecmerge emerge kdiff3 meld opendiff