diff --git a/src/managesieve/main.c b/src/managesieve/main.c
index 19d3f06668426213337b6c6589ae850c1826f2fe..4ce612deb6f4877e79c73a3b361188f08b24673c 100644
--- a/src/managesieve/main.c
+++ b/src/managesieve/main.c
@@ -358,6 +358,7 @@ int main(int argc, char *argv[])
 
 	/* Dump capabilities if requested */
 	if (getenv("DUMP_CAPABILITY") != NULL) {
+		i_set_debug_file("/dev/null");
 		managesieve_capabilities_dump();
 		commands_deinit();
 		master_service_deinit(&master_service);