diff --git a/src/tcpoutbuffer.h b/src/tcpoutbuffer.h
index 1bbfa4d..6ebd5fa 100644
--- a/src/tcpoutbuffer.h
+++ b/src/tcpoutbuffer.h
@@ -19,6 +19,13 @@
 #include <sys/ioctl.h>
 #include <sys/uio.h>
  
+/**
+ *  FIONREAD on Solaris is defined elsewhere
+ */
+#ifdef __sun
+#include <sys/filio.h>
+#endif
+
 /**
  *  Set up namespace
  */