diff --git a/ext/libnatpmp/getgateway.c b/ext/libnatpmp/getgateway.c
index 7f3141521..f743a0894 100644
--- a/ext/libnatpmp/getgateway.c
+++ b/ext/libnatpmp/getgateway.c
@@ -53,6 +53,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #undef USE_PROC_NET_ROUTE
 #define USE_SOCKET_ROUTE
 #undef USE_SYSCTL_NET_ROUTE
+#include <sys/sysctl.h>
 #endif
 
 #ifdef __APPLE__
diff --git a/osdep/ManagedRoute.cpp b/osdep/ManagedRoute.cpp
index 264866fc1..0bb74c1a4 100644
--- a/osdep/ManagedRoute.cpp
+++ b/osdep/ManagedRoute.cpp
@@ -42,6 +42,7 @@
 #include <net/if.h>
 #ifdef __BSD__
 #include <net/if_dl.h>
+#include <sys/sysctl.h>
 #endif
 #include <ifaddrs.h>
 #endif
diff --git a/osdep/OSXEthernetTap.cpp b/osdep/OSXEthernetTap.cpp
index e5361ce41..b3580929a 100644
--- a/osdep/OSXEthernetTap.cpp
+++ b/osdep/OSXEthernetTap.cpp
@@ -43,6 +43,7 @@
 #include <net/if_arp.h>
 #include <net/if_dl.h>
 #include <net/if_media.h>
+#include <sys/sysctl.h>
 #include <netinet6/in6_var.h>
 #include <netinet/in_var.h>
 #include <netinet/icmp6.h>