diff --git a/include/arm9/fmt.h b/include/arm9/fmt.h
index d6dc629..97e94f3 100644
--- a/include/arm9/fmt.h
+++ b/include/arm9/fmt.h
@@ -32,8 +32,8 @@
 
 
 u32 ee_vsprintf(char *buf, const char *fmt, va_list args);
-u32 ee_sprintf(char *buf, const char *fmt, ...);
-u32 ee_snprintf(char *const buf, UNUSED u32 size, const char *const fmt, ...);
+__attribute__ ((format (printf, 2, 3))) u32 ee_sprintf(char *const buf, const char *const fmt, ...);
+__attribute__ ((format (printf, 3, 4))) u32 ee_snprintf(char *const buf, UNUSED u32 size, const char *const fmt, ...);
 u32 ee_vsnprintf(char *const buf, UNUSED u32 size, const char *const fmt, va_list arg);
-u32 ee_printf(const char *const fmt, ...);
+__attribute__ ((format (printf, 1, 2))) u32 ee_printf(const char *const fmt, ...);
 u32 ee_puts(const char *const str);
diff --git a/include/util.h b/include/util.h
index 91d079a..622c61c 100644
--- a/include/util.h
+++ b/include/util.h
@@ -28,7 +28,7 @@
 void wait(u32 cycles);
 
 
-int mysscanf(const char *s, const char *fmt, ...);
+__attribute__ ((format (scanf, 2, 3))) int mysscanf(const char *s, const char *fmt, ...);
 
 // case insensitive string compare function
 int strnicmp(const char *str1, const char *str2, u32 len);
diff --git a/source/arm9/fmt.c b/source/arm9/fmt.c
index 532b35b..42e5485 100644
--- a/source/arm9/fmt.c
+++ b/source/arm9/fmt.c
@@ -321,7 +321,7 @@
     return str - buf;
 }
 
-u32 ee_sprintf(char *const buf, const char *const fmt, ...)
+__attribute__ ((format (printf, 2, 3))) u32 ee_sprintf(char *const buf, const char *const fmt, ...)
 {
     va_list args;
     va_start(args, fmt);
@@ -331,7 +331,7 @@
     return res;
 }
 
-u32 ee_snprintf(char *const buf, UNUSED u32 size, const char *const fmt, ...)
+__attribute__ ((format (printf, 3, 4))) u32 ee_snprintf(char *const buf, UNUSED u32 size, const char *const fmt, ...)
 {
     va_list args;
     va_start(args, fmt);
@@ -346,7 +346,7 @@
     return ee_vsprintf(buf, fmt, arg);
 }
 
-u32 ee_printf(const char *const fmt, ...)
+__attribute__ ((format (printf, 1, 2))) u32 ee_printf(const char *const fmt, ...)
 {
     char buf[256];
     va_list args;
diff --git a/source/util.c b/source/util.c
index 4faa4b7..9b3bcf2 100644
--- a/source/util.c
+++ b/source/util.c
@@ -33,7 +33,7 @@
 	}
 }
 
-int mysscanf(const char *s, const char *fmt, ...)
+__attribute__ ((format (scanf, 2, 3))) int mysscanf(const char *s, const char *fmt, ...)
 {
 	va_list args;
 	va_start(args, fmt);