extern "C" used in skeletons

diff --git a/skeletons/constr_TYPE.h b/skeletons/constr_TYPE.h
index e36f293..90b6578 100644
--- a/skeletons/constr_TYPE.h
+++ b/skeletons/constr_TYPE.h
@@ -14,6 +14,10 @@
 #include <ber_tlv_length.h>
 #include <ber_tlv_tag.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct asn_TYPE_descriptor_s;	/* Forward declaration */
 struct asn_TYPE_member_s;	/* Forward declaration */
 
@@ -157,4 +161,8 @@
 	asn_TYPE_descriptor_t *td,	/* ASN.1 type descriptor */
 	const void *struct_ptr);	/* Structure to be printed */
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif	/* _CONSTR_TYPE_H_ */