diff --git a/parse-options.c b/parse-options.c
index b3d19446cd..70851a385b 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -841,6 +841,26 @@ static void show_negated_gitcomp(const struct option *opts, int show_all,
 	}
 }
 
+int parse_options_takes_argument(const struct option *opt)
+{
+	switch (opt->type) {
+	case OPTION_STRING:
+	case OPTION_FILENAME:
+	case OPTION_INTEGER:
+	case OPTION_UNSIGNED:
+	case OPTION_CALLBACK:
+		break;
+	default:
+		return 0;
+	}
+
+	if (opt->flags & (PARSE_OPT_NOARG | PARSE_OPT_OPTARG |
+			  PARSE_OPT_LASTARG_DEFAULT))
+		return 0;
+
+	return 1;
+}
+
 static int show_gitcomp(const struct option *opts, int show_all)
 {
 	const struct option *original_opts = opts;
@@ -862,20 +882,9 @@ static int show_gitcomp(const struct option *opts, int show_all)
 			break;
 		case OPTION_GROUP:
 			continue;
-		case OPTION_STRING:
-		case OPTION_FILENAME:
-		case OPTION_INTEGER:
-		case OPTION_UNSIGNED:
-		case OPTION_CALLBACK:
-			if (opts->flags & PARSE_OPT_NOARG)
-				break;
-			if (opts->flags & PARSE_OPT_OPTARG)
-				break;
-			if (opts->flags & PARSE_OPT_LASTARG_DEFAULT)
-				break;
-			suffix = "=";
-			break;
 		default:
+			if (parse_options_takes_argument(opts))
+				suffix = "=";
 			break;
 		}
 		if (opts->flags & PARSE_OPT_COMP_ARG)
diff --git a/parse-options.h b/parse-options.h
index abc73d8399..b96e93508e 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -420,6 +420,16 @@ int parse_options(int argc, const char **argv, const char *prefix,
 		  const char * const usagestr[],
 		  enum parse_opt_flags flags);
 
+/*
+ * Return non-zero if `opt` takes a value, which means that it consumes
+ * the next argument when that value is not stuck to it with an '='.
+ *
+ * Note that an option with PARSE_OPT_LASTARG_DEFAULT only consumes the
+ * next argument when it isn't the last one, so it is not considered as
+ * taking a value here.
+ */
+int parse_options_takes_argument(const struct option *opt);
+
 NORETURN void usage_with_options(const char * const *usagestr,
 				 const struct option *options);