diff --git a/libfuse/lib/debug.cpp b/libfuse/lib/debug.cpp
index b82bce98..e4fba572 100644
--- a/libfuse/lib/debug.cpp
+++ b/libfuse/lib/debug.cpp
@@ -1162,7 +1162,7 @@ debug_fuse_in_header(const struct fuse_in_header *hdr_)
   const void *arg = &hdr_[1];
 
   fmt::print(stderr,
-             "unique=0x%016" PRIx64 ";"
+             "unique=0x{:016x}";"
              " opcode=%s ({});"
              " nodeid={};"
              " uid={};"