diff --git a/test/test-device.c b/test/test-device.c
index 2d7ed71e..57631f1d 100644
--- a/test/test-device.c
+++ b/test/test-device.c
@@ -1421,6 +1421,7 @@ END_TEST
 
 char *debug_messages[64] = { NULL };
 
+LIBINPUT_ATTRIBUTE_PRINTF(3, 0)
 static void
 debug_log_handler(struct libinput *libinput,
 		  enum libinput_log_priority priority,
diff --git a/tools/libinput-debug-tablet.c b/tools/libinput-debug-tablet.c
index ceaee1d1..73948de2 100644
--- a/tools/libinput-debug-tablet.c
+++ b/tools/libinput-debug-tablet.c
@@ -72,6 +72,7 @@ struct context {
 	} abs;
 };
 
+LIBINPUT_ATTRIBUTE_PRINTF(1, 2)
 static void
 print_line(const char *format, ...)
 {
diff --git a/tools/libinput-quirks.c b/tools/libinput-quirks.c
index 173e5c22..047eb041 100644
--- a/tools/libinput-quirks.c
+++ b/tools/libinput-quirks.c
@@ -35,6 +35,7 @@
 
 static bool verbose = false;
 
+LIBINPUT_ATTRIBUTE_PRINTF(3, 0)
 static void
 log_handler(struct libinput *this_is_null,
 	    enum libinput_log_priority priority,