diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 68bb35ab791..a33a1311829 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -654,8 +654,12 @@ PostmasterMain(int argc, char *argv[])
 	 * a standalone backend, their default handling is reasonable.  Hence, all
 	 * child processes should just allow the inherited settings to stand.
 	 */
+#ifdef SIGTTIN
 	pqsignal(SIGTTIN, SIG_IGN); /* ignored */
+#endif
+#ifdef SIGTTOU
 	pqsignal(SIGTTOU, SIG_IGN); /* ignored */
+#endif
 
 	/* ignore SIGXFSZ, so that ulimit violations work like disk full */
 #ifdef SIGXFSZ
diff --git a/src/include/port/win32_port.h b/src/include/port/win32_port.h
index 360dbdf3a75..f9d351f20b7 100644
--- a/src/include/port/win32_port.h
+++ b/src/include/port/win32_port.h
@@ -171,8 +171,6 @@
 #define SIGTSTP				18
 #define SIGCONT				19
 #define SIGCHLD				20
-#define SIGTTIN				21
-#define SIGTTOU				22	/* Same as SIGABRT -- no problem, I hope */
 #define SIGWINCH			28
 #define SIGUSR1				30
 #define SIGUSR2				31