diff --git a/code/arraylist.h b/code/arraylist.h
index 5cf6ecfb..05788772 100644
--- a/code/arraylist.h
+++ b/code/arraylist.h
@@ -20,7 +20,7 @@
 #include <cstdlib>
 #include <cstring>
 #include <math.h>
-#include <new.h>
+#include <new>
 
 
 template <class T>
diff --git a/code/conquer.cpp b/code/conquer.cpp
index fbfc034c..5a0677e5 100644
--- a/code/conquer.cpp
+++ b/code/conquer.cpp
@@ -124,7 +124,9 @@
 #include <direct.h>
 #include <dos.h>
 #include <fcntl.h>
+#ifdef _WIN32
 #include <io.h>
+#endif
 #include <share.h>
 #include <span>
 
diff --git a/code/data.cpp b/code/data.cpp
index 2c510a0d..7c9a1107 100644
--- a/code/data.cpp
+++ b/code/data.cpp
@@ -37,7 +37,7 @@
 
 #include "data.h"
 
-#include <new.h>
+#include <new>
 
 HINSTANCE LanguageResources;
 
diff --git a/code/dbgprint.h b/code/dbgprint.h
index 49f70fed..176743d5 100644
--- a/code/dbgprint.h
+++ b/code/dbgprint.h
@@ -15,7 +15,11 @@
 
 #include "sun.h"
 
+#ifdef _WIN32
 #include <sal.h>
+#else
+#define _Printf_format_string_
+#endif
 
 void Debug_Init(void);
 void Debug_Init_Console(void);
diff --git a/code/except.h b/code/except.h
index 401a1142..abfde6d6 100644
--- a/code/except.h
+++ b/code/except.h
@@ -33,7 +33,11 @@
 
 #include "win.h"
 
+#ifdef _WIN32
 #include <sal.h>
+#else
+#define _Printf_format_string_
+#endif
 
 // Posted to the main window so that a requested test fault happens inside window procedure
 // dispatch, which the operating system unwinds differently from an ordinary call.
diff --git a/code/lcw.cpp b/code/lcw.cpp
index 82f5b5c5..7a1a4d92 100644
--- a/code/lcw.cpp
+++ b/code/lcw.cpp
@@ -34,6 +34,8 @@
 #include	"always.h"
 #include	"lcw.h"
 
+#include <cstddef>
+
 
 /// <summary>
 /// Decompresses an LCW encoded data block.
diff --git a/code/newdel.cpp b/code/newdel.cpp
index 6f49bd1f..7f129e8e 100644
--- a/code/newdel.cpp
+++ b/code/newdel.cpp
@@ -17,7 +17,7 @@
 #ifdef STEVES_NEW_CATCHER
 
 #include <crtdbg.h>
-#include <new.h>
+#include <new>
 
 
 /// <summary>
diff --git a/code/sha.cpp b/code/sha.cpp
index df04f76e..85bdbfc4 100644
--- a/code/sha.cpp
+++ b/code/sha.cpp
@@ -78,7 +78,7 @@ void SHAEngine::Process_Partial(void const * & data, int & length)
 	**	Attach as many bytes as possible from the source data into
 	**	the staging buffer.
 	*/
-	int add_count = std::min((int)length, SRC_BLOCK_SIZE - PartialCount);
+	int add_count = std::min<int>((int)length, SRC_BLOCK_SIZE - PartialCount);
 	memcpy(&Partial[PartialCount], data, add_count);
 	data = ((char const *&)data) + add_count;
 	PartialCount += add_count;
diff --git a/code/sha.h b/code/sha.h
index 2a2887ce..e74f2160 100644
--- a/code/sha.h
+++ b/code/sha.h
@@ -35,7 +35,7 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
-#include <new.h>
+#include <new>
 
 
 /*
diff --git a/code/startup.cpp b/code/startup.cpp
index 22199f90..279acc90 100644
--- a/code/startup.cpp
+++ b/code/startup.cpp
@@ -160,7 +160,9 @@
 #include <shellapi.h>
 
 #include <conio.h>
+#ifdef _WIN32
 #include <io.h>
+#endif
 #include <cfloat>
 #include <string>
 #include <vector>
diff --git a/code/techtype.cpp b/code/techtype.cpp
index 5ea075a1..80cbf741 100644
--- a/code/techtype.cpp
+++ b/code/techtype.cpp
@@ -43,7 +43,7 @@
 #include "voc.hh"
 
 #include <algorithm>
-#include <new.h>
+#include <new>
 
 
 /***************************************************************************
diff --git a/code/visualc.h b/code/visualc.h
index 9fa9a912..ca9c57a9 100644
--- a/code/visualc.h
+++ b/code/visualc.h
@@ -116,6 +116,9 @@
 // Single precision pi, for the float paths that would otherwise round M_PI at every use.
 #define M_FPI 3.141592654f
 
+#endif
+
+
 /*
 **	Macros to convert between degrees and radians
 */
@@ -134,6 +137,3 @@
 #ifndef DEG_TO_RADF
 #define DEG_TO_RADF(x)	(((float)x)*M_PI/180.0f)
 #endif
-
-
-#endif
diff --git a/code/vqalib/cmp.h b/code/vqalib/cmp.h
index e00d166d..740fcbda 100644
--- a/code/vqalib/cmp.h
+++ b/code/vqalib/cmp.h
@@ -16,6 +16,7 @@
 
 #pragma once
 
+#include <cstddef>
 #include <cstdint>
 
 #if defined(__WATCOMC__) || defined(_MSC_VER)
diff --git a/code/vqalib/dstream.cpp b/code/vqalib/dstream.cpp
index ec4c3c03..f2b60fed 100644
--- a/code/vqalib/dstream.cpp
+++ b/code/vqalib/dstream.cpp
@@ -45,7 +45,15 @@
 #include	"vqaplayp.h"
 #include	<stdio.h>
 #include	<fcntl.h>
+#ifdef _WIN32
 #include	<io.h>
+#else
+#include	<unistd.h>
+#endif
+
+#ifndef O_BINARY
+#define O_BINARY 0
+#endif
 #include	<string.h>
 
 
diff --git a/code/wwfile.h b/code/wwfile.h
index 9ac186f9..426e1a59 100644
--- a/code/wwfile.h
+++ b/code/wwfile.h
@@ -40,7 +40,9 @@
 
 #include <cstddef>
 #include <cstdio>
+#ifdef _WIN32
 #include <io.h>
+#endif
 
 #ifndef SEEK_SET
 #define SEEK_SET					0	// Seek from start of file.