diff --git a/aclients.c b/aclients.c
index a579285..fe5e93c 100644
--- a/aclients.c
+++ b/aclients.c
@@ -67,6 +67,7 @@
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
+#include <arpa/inet.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <fcntl.h>
diff --git a/dwgpsd.c b/dwgpsd.c
index 5fc97bf..37688ff 100644
--- a/dwgpsd.c
+++ b/dwgpsd.c
@@ -41,6 +41,7 @@
 #include <string.h>
 #include <errno.h>
 #include <time.h>
+#include <math.h>
 
 #if __WIN32__
 #error Not for Windows
diff --git a/igate.c b/igate.c
index 4373857..6a716d1 100644
--- a/igate.c
+++ b/igate.c
@@ -78,6 +78,7 @@
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
+#include <arpa/inet.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #endif
diff --git a/ttcalc.c b/ttcalc.c
index b122be4..17538e3 100644
--- a/ttcalc.c
+++ b/ttcalc.c
@@ -57,6 +57,7 @@
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
+#include <arpa/inet.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <sys/errno.h>