diff --git a/libfuse/lib/debug.cpp b/libfuse/lib/debug.cpp
index 23095f74..c86a1ada 100644
--- a/libfuse/lib/debug.cpp
+++ b/libfuse/lib/debug.cpp
@@ -273,7 +273,8 @@ fuse_debug_init_flag_name(const uint64_t flag_)
 
 static
 void
-debug_open_flags(const uint32_t flags_)
+debug_open_flags(FILE *,
+                 const uint32_t flags_)
 {
   fmt::print("{}, ",open_accmode_to_str(flags_));
   for(size_t i = 0; i < (sizeof(flags_) * 8); i++)
@@ -1163,7 +1164,7 @@ debug_fuse_in_header(const struct fuse_in_header *hdr_)
 {
   const void *arg = &hdr_[1];
 
-  fmt::print(stderr,
+  fmt::print(g_OUTPUT,
              "unique=0x{:016x};"
              " opcode={} ({});"
              " nodeid={};"