diff --git a/libfuse/lib/debug.cpp b/libfuse/lib/debug.cpp
index ab60a089..498d17d4 100644
--- a/libfuse/lib/debug.cpp
+++ b/libfuse/lib/debug.cpp
@@ -1280,7 +1280,7 @@ debug_fuse_out_header(const struct fuse_out_header *hdr_)
              "unique=0x{:016x};"
              " opcode=RESPONSE;"
              " error={} ({});"
-             " len={};"
+             " len={};\n"
              ,
              hdr_->unique,
              hdr_->error,