diff --git a/public/build.h b/public/build.h
index 3692cf17..5b6bcc36 100644
--- a/public/build.h
+++ b/public/build.h
@@ -75,6 +75,7 @@ For more information, please refer to <http://unlicense.org/>
 #undef XASH_RISCV_DOUBLEFP
 #undef XASH_RISCV_SINGLEFP
 #undef XASH_RISCV_SOFTFP
+#undef XASH_SERENITY
 #undef XASH_WIN32
 #undef XASH_WIN64
 #undef XASH_X86
@@ -126,6 +127,9 @@ For more information, please refer to <http://unlicense.org/>
 #elif defined __HAIKU__
 	#define XASH_HAIKU 1
 	#define XASH_POSIX 1
+#elif defined __serenity__
+	#define XASH_SERENITY 1
+	#define XASH_POSIX 1
 #else
 #error "Place your operating system name here! If this is a mistake, try to fix conditions above and report a bug"
 #endif
diff --git a/scripts/waifulib/library_naming.py b/scripts/waifulib/library_naming.py
index a3929067..44ade2fd 100644
--- a/scripts/waifulib/library_naming.py
+++ b/scripts/waifulib/library_naming.py
@@ -57,6 +57,7 @@ DEFINES = [
 'XASH_RISCV_DOUBLEFP',
 'XASH_RISCV_SINGLEFP',
 'XASH_RISCV_SOFTFP',
+'XASH_SERENITY',
 'XASH_WIN32',
 'XASH_WIN64',
 'XASH_X86',
@@ -89,6 +90,8 @@ def configure(conf):
 		buildos = "dos4gw" # unused, just in case
 	elif conf.env.XASH_HAIKU:
 		buildos = "haiku"
+	elif conf.env.XASH_SERENITY:
+		buildos = "serenityos"
 	else:
 		conf.fatal("Place your operating system name in build.h and library_naming.py!\n"
 			"If this is a mistake, try to fix conditions above and report a bug")