diff --git a/share/completions/diff.fish b/share/completions/diff.fish
index aa2caf8b4..36ceec03d 100644
--- a/share/completions/diff.fish
+++ b/share/completions/diff.fish
@@ -24,3 +24,4 @@ complete -c diff -l to-file -r -d "Compare FILE2 to all operands"
 complete -c diff -s l -l paginate -d "Pass the output through 'pr'"
 complete -c diff -s v -l version -d "Display version and exit"
 complete -c diff -l help -d "Display help and exit"
+complete -c diff -l color -d "Colorize the output"