diff --git a/contrib/tig-completion.bash b/contrib/tig-completion.bash
index 5aef3fd..cec0632 100755
--- a/contrib/tig-completion.bash
+++ b/contrib/tig-completion.bash
@@ -29,6 +29,10 @@
 #       at source time then all lookups will be done on demand,
 #       which may be slightly slower.
 
+if ! type -f __git_complete &>/dev/null; then
+	__git_complete() { complete "${1}"; }
+fi
+
 __tig_options="
 	-v --version
 	-h --help