diff --git a/upnp/inc/TemplateInclude.h b/upnp/inc/TemplateInclude.h
index 4e8c877..79ea834 100644
--- a/upnp/inc/TemplateInclude.h
+++ b/upnp/inc/TemplateInclude.h
@@ -95,10 +95,10 @@
 	/*! DOC_##CLASS##_##MEMBER */ \
 	EXPORT_SPEC const UpnpString *CLASS##_get_##MEMBER(const CLASS *p); \
 	EXPORT_SPEC int CLASS##_set_##MEMBER(CLASS *p, const UpnpString *s); \
-	EXPORT_SPEC int CLASS##_get_##MEMBER##_Length(const CLASS *p); \
+	EXPORT_SPEC size_t CLASS##_get_##MEMBER##_Length(const CLASS *p); \
 	EXPORT_SPEC const char *CLASS##_get_##MEMBER##_cstr(const CLASS *p); \
 	EXPORT_SPEC int CLASS##_strcpy_##MEMBER(CLASS *p, const char *s); \
-	EXPORT_SPEC int CLASS##_strncpy_##MEMBER(CLASS *p, const char *s, int n); \
+	EXPORT_SPEC int CLASS##_strncpy_##MEMBER(CLASS *p, const char *s, size_t n); \
 	EXPORT_SPEC void CLASS##_clear_##MEMBER(CLASS *p); \
 
 
diff --git a/upnp/inc/TemplateSource.h b/upnp/inc/TemplateSource.h
index 1e09f09..ef4744d 100644
--- a/upnp/inc/TemplateSource.h
+++ b/upnp/inc/TemplateSource.h
@@ -151,7 +151,7 @@ int CLASS##_set_##MEMBER(CLASS *p, const UpnpString *s) \
 	return UpnpString_set_String(((struct S##CLASS *)p)->m_##MEMBER, q); \
 } \
 \
-int CLASS##_get_##MEMBER##_Length(const CLASS *p) \
+size_t CLASS##_get_##MEMBER##_Length(const CLASS *p) \
 { \
 	return UpnpString_get_Length(CLASS##_get_##MEMBER(p)); \
 } \
@@ -165,7 +165,7 @@ int CLASS##_strcpy_##MEMBER(CLASS *p, const char *s) \
 	return UpnpString_set_String(((struct S##CLASS *)p)->m_##MEMBER, s); \
 } \
 \
-int CLASS##_strncpy_##MEMBER(CLASS *p, const char *s, int n) \
+int CLASS##_strncpy_##MEMBER(CLASS *p, const char *s, size_t n) \
 { \
 	return UpnpString_set_StringN(((struct S##CLASS *)p)->m_##MEMBER, s, n); \
 } \