diff --git a/mem-pool.h b/mem-pool.h
index d1c66413ec..321d86a63c 100644
--- a/mem-pool.h
+++ b/mem-pool.h
@@ -50,6 +50,7 @@ char *mem_pool_strndup(struct mem_pool *pool, const char *str, size_t len);
 /*
  * Allocate memory from the memory pool and format a string into it.
  */
+__attribute__((format (printf, 2, 3)))
 char *mem_pool_strfmt(struct mem_pool *pool, const char *fmt, ...);
 
 /*
diff --git a/scalar.c b/scalar.c
index 552ac8f0d9..363341b957 100644
--- a/scalar.c
+++ b/scalar.c
@@ -289,6 +289,7 @@ static int unregister_dir(void)
 }
 
 /* printf-style interface, expects `<key>=<value>` argument */
+__attribute__((format (printf, 1, 2)))
 static int set_config(const char *fmt, ...)
 {
 	struct strbuf buf = STRBUF_INIT;
diff --git a/wt-status.c b/wt-status.c
index bdfc23e2ae..a12406eee0 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -126,6 +126,7 @@ void status_printf(struct wt_status *s, const char *color,
 	va_end(ap);
 }
 
+__attribute__((format (printf, 3, 4)))
 static void status_printf_more(struct wt_status *s, const char *color,
 			       const char *fmt, ...)
 {