diff --git a/dlls/nsiproxy.sys/icmp_echo.c b/dlls/nsiproxy.sys/icmp_echo.c
index 999b53186c2..955fdfdb979 100644
--- a/dlls/nsiproxy.sys/icmp_echo.c
+++ b/dlls/nsiproxy.sys/icmp_echo.c
@@ -21,8 +21,6 @@
 #pragma makedep unix
 #endif
 
-#define _NTSYSTEM_
-
 #include "config.h"
 #include <stdarg.h>
 
diff --git a/dlls/nsiproxy.sys/ip.c b/dlls/nsiproxy.sys/ip.c
index c7ec2e89b16..432fe9d8e65 100644
--- a/dlls/nsiproxy.sys/ip.c
+++ b/dlls/nsiproxy.sys/ip.c
@@ -22,8 +22,6 @@
 #pragma makedep unix
 #endif
 
-#define _NTSYSTEM_
-
 #include "config.h"
 #include <stdarg.h>
 
diff --git a/dlls/winepulse.drv/pulse.c b/dlls/winepulse.drv/pulse.c
index 2e6ad4848eb..bce70ac358c 100644
--- a/dlls/winepulse.drv/pulse.c
+++ b/dlls/winepulse.drv/pulse.c
@@ -22,8 +22,6 @@
 #pragma makedep unix
 #endif
 
-#define _NTSYSTEM_
-
 #include <stdarg.h>
 #include <pthread.h>
 #include <math.h>
diff --git a/include/winnt.h b/include/winnt.h
index c230fa0cd7f..87051289445 100644
--- a/include/winnt.h
+++ b/include/winnt.h
@@ -41,7 +41,7 @@
 extern "C" {
 #endif
 
-#ifdef _NTSYSTEM_
+#if defined(_NTSYSTEM_) || defined(WINE_UNIX_LIB)
 #define NTSYSAPI
 #else
 #define NTSYSAPI DECLSPEC_IMPORT