builtin/gc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/builtin/gc.c b/builtin/gc.c
index 3e67124ea..a4b20aaaf 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -354,6 +354,7 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 	const char *name;
 	pid_t pid;
 	int daemonized = 0;
+	timestamp_t dummy;
 
 	struct option builtin_gc_options[] = {
 		OPT__QUIET(&quiet, N_("suppress progress reporting")),
@@ -392,6 +393,9 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 	if (argc > 0)
 		usage_with_options(builtin_gc_usage, builtin_gc_options);
 
+	if (parse_expiry_date(prune_expire, &dummy))
+		die(_("Failed to parse prune expiry value %s"), prune_expire);
+
 	if (aggressive) {
 		argv_array_push(&repack, "-f");
 		if (aggressive_depth > 0)