diff --git a/hal/serial/win32/serial_port_win32.c b/hal/serial/win32/serial_port_win32.c
index 19eb30bf..186cd214 100644
--- a/hal/serial/win32/serial_port_win32.c
+++ b/hal/serial/win32/serial_port_win32.c
@@ -24,7 +24,7 @@
 #include <stdint.h>
 #include <stdio.h>
 
-#include <Windows.h>
+#include <windows.h>
 
 #include "lib_memory.h"
 
diff --git a/make/target_system.mk b/make/target_system.mk
index b03a0ec7..0812fd6b 100644
--- a/make/target_system.mk
+++ b/make/target_system.mk
@@ -167,7 +167,7 @@ CFLAGS += -arch i386
 LDFLAGS += -arch i386
 endif
 
-ifeq ($(TARGET), WIN32)
+ifdef WINDOWS
 DYN_LIB_NAME = $(LIB_OBJS_DIR)/iec61850.dll
 else