Fix macOS build

[exim.git] / src / OS / os.h-Linux

diff --git a/src/OS/os.h-Linux b/src/OS/os.h-Linux
index 539eeea330a4a1a2995df8a02c70426806c4ea38..63cf9babd36aa04e4b64ef747b7edc091c4703a1 100644 (file)
--- a/src/OS/os.h-Linux
+++ b/src/OS/os.h-Linux
@@ -83,6 +83,9 @@ then change the 0 to 1 in the next block. */
 # define MSG_FASTOPEN 0x20000000
 #endif
 #define EXIM_HAVE_TCPI_UNACKED
+#ifndef TCPI_OPT_SYN_DATA
+# define TCPI_OPT_SYN_DATA 32
+#endif
 
 
 /* End */