diff --git a/Libraries/LibC/stddef.h b/Libraries/LibC/stddef.h
index 340d409f88..17c03e7f97 100644
--- a/Libraries/LibC/stddef.h
+++ b/Libraries/LibC/stddef.h
@@ -39,9 +39,4 @@
 typedef __PTRDIFF_TYPE__ ptrdiff_t;
 typedef __SIZE_TYPE__ size_t;
 
-/* There is no __SSIZE_TYPE__ but we can trick the preprocessor into defining it for us anyway! */
-#define unsigned signed
-typedef __SIZE_TYPE__ ssize_t;
-#undef unsigned
-
 #endif
diff --git a/Libraries/LibC/sys/types.h b/Libraries/LibC/sys/types.h
index 43d4e7e0dd..35833fbf75 100644
--- a/Libraries/LibC/sys/types.h
+++ b/Libraries/LibC/sys/types.h
@@ -32,6 +32,11 @@
 
 __BEGIN_DECLS
 
+/* There is no __SSIZE_TYPE__ but we can trick the preprocessor into defining it for us anyway! */
+#define unsigned signed
+typedef __SIZE_TYPE__ ssize_t;
+#undef unsigned
+
 typedef unsigned char u_char;
 typedef unsigned short u_short;
 typedef unsigned int u_int;