diff --git a/src/libcharon/plugins/kernel_pfkey/kernel_pfkey_ipsec.c b/src/libcharon/plugins/kernel_pfkey/kernel_pfkey_ipsec.c
index 347bada5c..dbf7721f9 100644
--- a/src/libcharon/plugins/kernel_pfkey/kernel_pfkey_ipsec.c
+++ b/src/libcharon/plugins/kernel_pfkey/kernel_pfkey_ipsec.c
@@ -67,8 +67,10 @@
 
 /** non linux specific */
 #ifndef IPPROTO_COMP
+#ifdef IPPROTO_IPCOMP
 #define IPPROTO_COMP IPPROTO_IPCOMP
 #endif
+#endif
 
 #ifndef SADB_X_AALG_SHA2_256HMAC
 #define SADB_X_AALG_SHA2_256HMAC SADB_X_AALG_SHA2_256