diff --git a/flash.h b/flash.h
index 84ee511..cf3bd21 100644
--- a/flash.h
+++ b/flash.h
@@ -591,7 +591,8 @@
 #define NT 1    /* Not tested */
 
 /* cli_output.c */
-int print(int type, const char *fmt, ...);
+/* Let gcc and clang check for correct printf-style format strings. */
+int print(int type, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
 #define MSG_ERROR	0
 #define MSG_INFO	1
 #define MSG_DEBUG	2
diff --git a/flashrom.c b/flashrom.c
index 8a97454..73145a9 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -394,7 +394,7 @@
 int register_shutdown(void (*function) (void *data), void *data)
 {
 	if (shutdown_fn_count >= SHUTDOWN_MAXFN) {
-		msg_perr("Tried to register more than %n shutdown functions.\n",
+		msg_perr("Tried to register more than %i shutdown functions.\n",
 			 SHUTDOWN_MAXFN);
 		return 1;
 	}
diff --git a/udelay.c b/udelay.c
index b395971..8bfba63 100644
--- a/udelay.c
+++ b/udelay.c
@@ -91,7 +91,7 @@
 	msg_pinfo("Calibrating delay loop... ");
 	resolution = measure_os_delay_resolution();
 	if (resolution) {
-		msg_pdbg("OS timer resolution is %u usecs, ", resolution);
+		msg_pdbg("OS timer resolution is %lu usecs, ", resolution);
 	} else {
 		msg_pinfo("OS timer resolution is unusable. ");
 	}