diff --git a/tools/virtiofsd/fuse_log.c b/tools/virtiofsd/fuse_log.c
index 745d88c..2de3f48 100644
--- a/tools/virtiofsd/fuse_log.c
+++ b/tools/virtiofsd/fuse_log.c
@@ -12,6 +12,7 @@
 #include "fuse_log.h"
 
 
+G_GNUC_PRINTF(2, 0)
 static void default_log_func(__attribute__((unused)) enum fuse_log_level level,
                              const char *fmt, va_list ap)
 {
diff --git a/tools/virtiofsd/fuse_log.h b/tools/virtiofsd/fuse_log.h
index 8d7091b..e5c2967 100644
--- a/tools/virtiofsd/fuse_log.h
+++ b/tools/virtiofsd/fuse_log.h
@@ -45,7 +45,8 @@
  * @param ap format string arguments
  */
 typedef void (*fuse_log_func_t)(enum fuse_log_level level, const char *fmt,
-                                va_list ap);
+                                va_list ap)
+    G_GNUC_PRINTF(2, 0);
 
 /**
  * Install a custom log handler function.
@@ -68,6 +69,7 @@
  * @param level severity level (FUSE_LOG_ERR, FUSE_LOG_DEBUG, etc)
  * @param fmt sprintf-style format string including newline
  */
-void fuse_log(enum fuse_log_level level, const char *fmt, ...);
+void fuse_log(enum fuse_log_level level, const char *fmt, ...)
+    G_GNUC_PRINTF(2, 3);
 
 #endif /* FUSE_LOG_H_ */
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 20f0f41..40ea2ed 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -4182,6 +4182,7 @@
     }
 }
 
+G_GNUC_PRINTF(2, 0)
 static void log_func(enum fuse_log_level level, const char *fmt, va_list ap)
 {
     g_autofree char *localfmt = NULL;