diff --git a/frontpanel/FrontPanelTest.c b/frontpanel/FrontPanelTest.c
index 97f60078..d64bef02 100644
--- a/frontpanel/FrontPanelTest.c
+++ b/frontpanel/FrontPanelTest.c
@@ -41,6 +41,7 @@
 
 #if defined(_WIN32)
 #include <windows.h>
+#include <winerror.h>
 #define usleep(n) Sleep(n/1000)
 #else
 #include <unistd.h>
diff --git a/sim_console.c b/sim_console.c
index cdd2c90a..14aab8ee 100644
--- a/sim_console.c
+++ b/sim_console.c
@@ -3285,7 +3285,6 @@ return SCPE_OK;
 
 #include <fcntl.h>
 #include <io.h>
-#include <windows.h>
 #define RAW_MODE 0
 static HANDLE std_input;
 static HANDLE std_output;
diff --git a/sim_defs.h b/sim_defs.h
index ecbd5109..fd24e958 100644
--- a/sim_defs.h
+++ b/sim_defs.h
@@ -127,6 +127,7 @@ extern int sim_vax_snprintf(char *buf, size_t buf_size, const char *fmt, ...);
 
 #ifdef _WIN32
 #include <winsock2.h>
+#include <windows.h>
 #include <winerror.h>
 #undef PACKED                       /* avoid macro name collision */
 #undef ERROR                        /* avoid macro name collision */
diff --git a/sim_disk.c b/sim_disk.c
index 5a9d779c..b8374a3c 100644
--- a/sim_disk.c
+++ b/sim_disk.c
@@ -80,9 +80,6 @@ Internal routines:
 #include <ctype.h>
 #include <sys/stat.h>
 
-#ifdef _WIN32
-#include <windows.h>
-#endif
 #if defined SIM_ASYNCH_IO
 #include <pthread.h>
 #endif
diff --git a/sim_frontpanel.c b/sim_frontpanel.c
index e6a3ab92..ed41f782 100644
--- a/sim_frontpanel.c
+++ b/sim_frontpanel.c
@@ -63,6 +63,7 @@ extern "C" {
 #if defined(_WIN32)
 #include <process.h>
 #include <windows.h>
+#include <winerror.h>
 #define sleep(n) Sleep(n*1000)
 #define msleep(n) Sleep(n)
 #define strtoull _strtoui64