diff --git a/include/psxtypes/arch/nt32/ntalltypes.h b/include/psxtypes/arch/nt32/ntalltypes.h
index 5e61552..f6d0718 100644
--- a/include/psxtypes/arch/nt32/ntalltypes.h
+++ b/include/psxtypes/arch/nt32/ntalltypes.h
@@ -176,3 +176,5 @@ typedef float			float_t;
 typedef double			double_t;
 #define __DEFINED_double_t
 #endif
+
+typedef __CUSTOM_OR_BUILTIN_va_list__ va_list;
diff --git a/include/psxtypes/arch/nt64/ntalltypes.h b/include/psxtypes/arch/nt64/ntalltypes.h
index d6640f8..20ddb75 100644
--- a/include/psxtypes/arch/nt64/ntalltypes.h
+++ b/include/psxtypes/arch/nt64/ntalltypes.h
@@ -176,3 +176,5 @@ typedef float			float_t;
 typedef double			double_t;
 #define __DEFINED_double_t
 #endif
+
+typedef __CUSTOM_OR_BUILTIN_va_list__ va_list;