diff --git a/headers/pmdsky.h b/headers/pmdsky.h
index e43dfdca..0a13b409 100644
--- a/headers/pmdsky.h
+++ b/headers/pmdsky.h
@@ -48,8 +48,12 @@ typedef short int16_t;
 typedef int int32_t;
 typedef long long int64_t;
 
+// C23 made `bool` a keyword that can't be overwritten
+#if __STDC_VERSION__ < 202311L
 // Define the bool type to be 1 byte
 typedef uint8_t bool;
+#endif
+ASSERT_SIZE(bool, 1);
 
 // Define size_t for convenience
 typedef unsigned long size_t;