diff --git a/assemble.c b/assemble.c
index 6adaec6a..c3a90492 100644
--- a/assemble.c
+++ b/assemble.c
@@ -82,6 +82,8 @@
  *		   used for conditional jump over longer jump
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <string.h>
 #include <inttypes.h>
diff --git a/compiler.h b/compiler.h
index 798466fe..0f7261c8 100644
--- a/compiler.h
+++ b/compiler.h
@@ -13,15 +13,25 @@
  *
  * Compiler-specific macros for NASM.  Feel free to add support for
  * other compilers in here.
+ *
+ * This header file should be included before any other header.
  */
 
-#ifndef COMPILER_H
-#define COMPILER_H 1
+#ifndef NASM_COMPILER_H
+#define NASM_COMPILER_H 1
 
 #ifdef HAVE_CONFIG_H
 # include "config.h"
 #endif
 
+/* Request as many features as we can */
+#define _GNU_SOURCE
+#define _ISO99_SOURCE
+#define _POSIX_SOURCE
+#define _POSIX_C_SOURCE		200112L
+#define _XOPEN_SOURCE		600
+#define _XOPEN_SOURCE_EXTENDED
+
 #ifdef __GNUC__
 # if __GNUC__ >= 4
 #  define HAVE_GNUC_4
@@ -38,9 +48,9 @@
 #endif
 
 /* Some versions of MSVC have these only with underscores in front */
-#include <stdio.h>
 #include <stddef.h>
 #include <stdarg.h>
+#include <stdio.h>
 
 #ifndef HAVE_SNPRINTF
 # ifdef HAVE__SNPRINTF
@@ -58,4 +68,4 @@ int vsnprintf(char *, size_t, const char *, va_list);
 # endif
 #endif
 
-#endif	/* COMPILER_H */
+#endif	/* NASM_COMPILER_H */
diff --git a/configure.in b/configure.in
index b97f536c..009720a2 100644
--- a/configure.in
+++ b/configure.in
@@ -82,6 +82,9 @@ fi
 dnl Check for <inttypes.h> or add a substitute version
 AC_CHECK_HEADERS(inttypes.h, , CFLAGS="$CFLAGS -I\$(top_srcdir)/inttypes")
 
+dnl The standard header for str*casecmp is <strings.h>
+AC_CHECK_HEADERS(strings.h)
+
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
 AC_TYPE_SIZE_T
@@ -107,6 +110,10 @@ if $missing; then
    XOBJS="$XOBJS lib/snprintf.o"
 fi
 
+AC_CHECK_FUNCS(strcasecmp stricmp)
+AC_CHECK_FUNCS(strncasecmp strnicmp)
+AC_CHECK_FUNCS(strsep)
+
 AC_CHECK_FUNCS(getuid)
 AC_CHECK_FUNCS(getgid)
 
diff --git a/crc64.c b/crc64.c
index da41e7db..fc165b78 100644
--- a/crc64.c
+++ b/crc64.c
@@ -1,3 +1,4 @@
+#include "compiler.h"
 #include <inttypes.h>
 #include <ctype.h>
 
diff --git a/disasm.c b/disasm.c
index 724d0bf6..dc754707 100644
--- a/disasm.c
+++ b/disasm.c
@@ -8,6 +8,8 @@
  * initial version 27/iii/95 by Simon Tatham
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <string.h>
 #include <limits.h>
diff --git a/eval.c b/eval.c
index a75c5bae..aa564e2f 100644
--- a/eval.c
+++ b/eval.c
@@ -8,6 +8,8 @@
  * initial version 27/iii/95 by Simon Tatham
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>
diff --git a/float.c b/float.c
index 357bcb74..64a77b86 100644
--- a/float.c
+++ b/float.c
@@ -8,6 +8,8 @@
  * initial version 13/ix/96 by Simon Tatham
  */
 
+#include "compiler.h"
+
 #include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/hashtbl.c b/hashtbl.c
index cbe2a1b9..5dd743db 100644
--- a/hashtbl.c
+++ b/hashtbl.c
@@ -4,6 +4,8 @@
  * Efficient dictionary hash table class.
  */
 
+#include "compiler.h"
+
 #include <inttypes.h>
 #include <string.h>
 #include "nasm.h"
diff --git a/labels.c b/labels.c
index 5a1fd132..2d2630d9 100644
--- a/labels.c
+++ b/labels.c
@@ -6,6 +6,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
diff --git a/lib/snprintf.c b/lib/snprintf.c
index f56a492a..de4d96da 100644
--- a/lib/snprintf.c
+++ b/lib/snprintf.c
@@ -4,6 +4,8 @@
  * Implement snprintf() in terms of vsnprintf()
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
diff --git a/lib/vsnprintf.c b/lib/vsnprintf.c
index 2c9399a0..976b0eac 100644
--- a/lib/vsnprintf.c
+++ b/lib/vsnprintf.c
@@ -5,6 +5,8 @@
  * that don't have them...
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
diff --git a/listing.c b/listing.c
index 1d432e55..226a026e 100644
--- a/listing.c
+++ b/listing.c
@@ -8,6 +8,8 @@
  * initial version 2/vii/97 by Simon Tatham
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>
diff --git a/macros.pl b/macros.pl
index 0934d174..596277dc 100644
--- a/macros.pl
+++ b/macros.pl
@@ -19,7 +19,7 @@ undef $tasm_count;
 open(OUTPUT,">macros.c") or die "unable to open macros.c\n";
     
 print OUTPUT "/* This file auto-generated from standard.mac by macros.pl" .
-" - don't edit it */\n\n#include <stddef.h>\n\nstatic const char *stdmac[] = {\n";
+" - don't edit it */\n\n#include \"compiler.h\"\n\nstatic const char *stdmac[] = {\n";
     
 foreach $fname ( @ARGV ) {
     open(INPUT,$fname) or die "unable to open $fname\n";
diff --git a/nasm.c b/nasm.c
index 7a4ac550..b28f4f77 100644
--- a/nasm.c
+++ b/nasm.c
@@ -6,6 +6,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>
diff --git a/nasm.h b/nasm.h
index a120ccda..3c491306 100644
--- a/nasm.h
+++ b/nasm.h
@@ -11,10 +11,11 @@
 #ifndef NASM_NASM_H
 #define NASM_NASM_H
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <inttypes.h>
 #include "version.h"            /* generated NASM version macros */
-#include "compiler.h"
 #include "nasmlib.h"
 #include "insnsi.h"		/* For enum opcode */
 
diff --git a/nasmlib.c b/nasmlib.c
index 6f0e6afd..d045a2ae 100644
--- a/nasmlib.c
+++ b/nasmlib.c
@@ -6,6 +6,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -144,7 +146,7 @@ char *nasm_strndup(char *s, size_t len)
     return p;
 }
 
-#if !defined(stricmp) && !defined(strcasecmp)
+#ifndef nasm_stricmp
 int nasm_stricmp(const char *s1, const char *s2)
 {
     while (*s1 && tolower(*s1) == tolower(*s2))
@@ -158,7 +160,7 @@ int nasm_stricmp(const char *s1, const char *s2)
 }
 #endif
 
-#if !defined(strnicmp) && !defined(strncasecmp)
+#ifndef nasm_strnicmp
 int nasm_strnicmp(const char *s1, const char *s2, int n)
 {
     while (n > 0 && *s1 && tolower(*s1) == tolower(*s2))
@@ -172,7 +174,7 @@ int nasm_strnicmp(const char *s1, const char *s2, int n)
 }
 #endif
 
-#if !defined(strsep)
+#ifndef nasm_strsep
 char *nasm_strsep(char **stringp, const char *delim)
 {
         char *s = *stringp;
diff --git a/nasmlib.h b/nasmlib.h
index a2544fc1..64afa450 100644
--- a/nasmlib.h
+++ b/nasmlib.h
@@ -9,9 +9,14 @@
 #ifndef NASM_NASMLIB_H
 #define NASM_NASMLIB_H
 
+#include "compiler.h"
+
 #include <inttypes.h>
 #include <stdio.h>
-#include "compiler.h"
+#include <string.h>
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
 
 /*
  * If this is defined, the wrappers around malloc et al will
@@ -98,27 +103,23 @@ char *nasm_strndup_log(char *, int, char *, size_t);
  * ANSI doesn't guarantee the presence of `stricmp' or
  * `strcasecmp'.
  */
-#if defined(stricmp) || defined(strcasecmp)
-#if defined(stricmp)
-#define nasm_stricmp stricmp
-#else
+#if defined(HAVE_STRCASECMP)
 #define nasm_stricmp strcasecmp
-#endif
+#elif defined(HAVE_STRICMP)
+#define nasm_stricmp stricmp
 #else
 int nasm_stricmp(const char *, const char *);
 #endif
 
-#if defined(strnicmp) || defined(strncasecmp)
-#if defined(strnicmp)
-#define nasm_strnicmp strnicmp
-#else
+#if defined(HAVE_STRNCASECMP)
 #define nasm_strnicmp strncasecmp
-#endif
+#elif defined(HAVE_STRNICMP)
+#define nasm_strnicmp strnicmp
 #else
 int nasm_strnicmp(const char *, const char *, int);
 #endif
 
-#if defined(strsep)
+#if defined(HAVE_STRSEP)
 #define nasm_strsep strsep
 #else
 char *nasm_strsep(char **stringp, const char *delim);
diff --git a/ndisasm.c b/ndisasm.c
index ea4dc537..a6664315 100644
--- a/ndisasm.c
+++ b/ndisasm.c
@@ -6,6 +6,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>
diff --git a/outform.c b/outform.c
index 1cdd5be8..3f4d18ff 100644
--- a/outform.c
+++ b/outform.c
@@ -9,6 +9,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <string.h>
 #include <inttypes.h>
diff --git a/output/outaout.c b/output/outaout.c
index d5358b4c..6c9bf242 100644
--- a/output/outaout.c
+++ b/output/outaout.c
@@ -7,6 +7,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outas86.c b/output/outas86.c
index 135ddda3..4bfbb04b 100644
--- a/output/outas86.c
+++ b/output/outas86.c
@@ -7,6 +7,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outbin.c b/output/outbin.c
index a1c51c8f..b5a7524c 100644
--- a/output/outbin.c
+++ b/output/outbin.c
@@ -44,6 +44,8 @@
 
 */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outcoff.c b/output/outcoff.c
index 8eb8c061..44a41e5a 100644
--- a/output/outcoff.c
+++ b/output/outcoff.c
@@ -7,6 +7,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outdbg.c b/output/outdbg.c
index 0dda75a6..43c6504a 100644
--- a/output/outdbg.c
+++ b/output/outdbg.c
@@ -7,6 +7,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outelf32.c b/output/outelf32.c
index fbc98d60..ca918487 100644
--- a/output/outelf32.c
+++ b/output/outelf32.c
@@ -7,6 +7,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outelf64.c b/output/outelf64.c
index e87d8bdc..5f77bb12 100644
--- a/output/outelf64.c
+++ b/output/outelf64.c
@@ -7,6 +7,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outieee.c b/output/outieee.c
index 19b25755..145fcafe 100644
--- a/output/outieee.c
+++ b/output/outieee.c
@@ -36,6 +36,8 @@
  *
  * David Lindauer, LADsoft
  */
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outmacho.c b/output/outmacho.c
index 86700f8e..545fa27f 100644
--- a/output/outmacho.c
+++ b/output/outmacho.c
@@ -10,6 +10,8 @@
 /* Most of this file is, like Mach-O itself, based on a.out. For more
  * guidelines see outaout.c.  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outobj.c b/output/outobj.c
index c411edd9..2f7079ef 100644
--- a/output/outobj.c
+++ b/output/outobj.c
@@ -7,6 +7,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outrdf.c b/output/outrdf.c
index cd311de5..d3fbb927 100644
--- a/output/outrdf.c
+++ b/output/outrdf.c
@@ -12,6 +12,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/output/outrdf2.c b/output/outrdf2.c
index c98beadd..82ac0ecb 100644
--- a/output/outrdf2.c
+++ b/output/outrdf2.c
@@ -9,6 +9,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/parser.c b/parser.c
index 31c3612a..fc1f0cf3 100644
--- a/parser.c
+++ b/parser.c
@@ -8,6 +8,8 @@
  * initial version 27/iii/95 by Simon Tatham
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>
diff --git a/pptok.pl b/pptok.pl
index f918e356..ee49648e 100755
--- a/pptok.pl
+++ b/pptok.pl
@@ -138,6 +138,7 @@ if ($what eq 'c') {
     
     die if ($n & ($n-1));
     
+    print OUT "#include \"compiler.h\"\n";
     print OUT "#include <inttypes.h>\n";
     print OUT "#include <ctype.h>\n";
     print OUT "#include \"nasmlib.h\"\n";
diff --git a/preproc.c b/preproc.c
index 1ee07ad6..5d97d1ec 100644
--- a/preproc.c
+++ b/preproc.c
@@ -34,6 +34,8 @@
  * detoken is used to convert the line back to text
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>
diff --git a/rdoff/collectn.c b/rdoff/collectn.c
index ad43d856..317c5286 100644
--- a/rdoff/collectn.c
+++ b/rdoff/collectn.c
@@ -4,8 +4,9 @@
  * This file is public domain.
  */
 
-#include "collectn.h"
+#include "compiler.h"
 #include <stdlib.h>
+#include "collectn.h"
 
 void collection_init(Collection * c)
 {
diff --git a/rdoff/hash.c b/rdoff/hash.c
index 34a8edc1..8b1d3cf8 100644
--- a/rdoff/hash.c
+++ b/rdoff/hash.c
@@ -8,6 +8,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include "hash.h"
 
 const uint32_t consttab[] = {
diff --git a/rdoff/ldrdf.c b/rdoff/ldrdf.c
index e28f2842..cd07fe72 100644
--- a/rdoff/ldrdf.c
+++ b/rdoff/ldrdf.c
@@ -24,6 +24,8 @@
  * under DOS. '#define STINGY_MEMORY' may help a little.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/rdoff/rdf2bin.c b/rdoff/rdf2bin.c
index e5561863..0b3f9999 100644
--- a/rdoff/rdf2bin.c
+++ b/rdoff/rdf2bin.c
@@ -2,6 +2,8 @@
  * rdf2bin.c - convert an RDOFF object file to flat binary
  */
 
+#include "compiler.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/rdoff/rdf2ihx.c b/rdoff/rdf2ihx.c
index a0238dad..94ba1cb3 100644
--- a/rdoff/rdf2ihx.c
+++ b/rdoff/rdf2ihx.c
@@ -4,6 +4,8 @@
  * Note that this program only writes 16-bit HEX.
  */
 
+#include "compiler.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/rdoff/rdfdump.c b/rdoff/rdfdump.c
index 691241d5..83305570 100644
--- a/rdoff/rdfdump.c
+++ b/rdoff/rdfdump.c
@@ -2,6 +2,8 @@
  * rdfdump.c - dump RDOFF file header.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/rdoff/rdflib.c b/rdoff/rdflib.c
index 6abd13cf..b4bf6d60 100644
--- a/rdoff/rdflib.c
+++ b/rdoff/rdflib.c
@@ -23,6 +23,8 @@
  * content size, followed by data.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
diff --git a/rdoff/rdfload.c b/rdoff/rdfload.c
index cd24c2de..063724e7 100644
--- a/rdoff/rdfload.c
+++ b/rdoff/rdfload.c
@@ -17,6 +17,8 @@
  *   - support for segment relocations (hard to do in ANSI C)
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/rdoff/rdlar.c b/rdoff/rdlar.c
index df813d12..1d4cd431 100644
--- a/rdoff/rdlar.c
+++ b/rdoff/rdlar.c
@@ -3,6 +3,8 @@
  * Copyright (c) 2002 RET & COM Research.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
diff --git a/rdoff/rdlib.c b/rdoff/rdlib.c
index c094a565..a6ae1568 100644
--- a/rdoff/rdlib.c
+++ b/rdoff/rdlib.c
@@ -2,6 +2,8 @@
  * rdlib.c - routines for manipulating RDOFF libraries (.rdl)
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/rdoff/rdoff.c b/rdoff/rdoff.c
index ac722795..25394996 100644
--- a/rdoff/rdoff.c
+++ b/rdoff/rdoff.c
@@ -15,6 +15,8 @@
  *		make it portable.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/rdoff/rdx.c b/rdoff/rdx.c
index 82210a65..26be0c41 100644
--- a/rdoff/rdx.c
+++ b/rdoff/rdx.c
@@ -12,6 +12,8 @@
    files. You can use these files in your own program to load RDOFF objects
    and execute the code in them in a similar way to what is shown here. */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 
diff --git a/rdoff/segtab.c b/rdoff/segtab.c
index 8ee1b7b3..e1a3ddf2 100644
--- a/rdoff/segtab.c
+++ b/rdoff/segtab.c
@@ -1,3 +1,5 @@
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include "segtab.h"
diff --git a/rdoff/symtab.c b/rdoff/symtab.c
index 6026ccd8..ce54d8ea 100644
--- a/rdoff/symtab.c
+++ b/rdoff/symtab.c
@@ -7,6 +7,9 @@
  * redistributable under the licence given in the file "Licence"
  * distributed in the NASM archive.
  */
+
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/regs.pl b/regs.pl
index 9dde6827..404c2f62 100755
--- a/regs.pl
+++ b/regs.pl
@@ -78,7 +78,7 @@ close(REGS);
 
 if ( $fmt eq 'h' ) {
     # Output regs.h
-    print "/* automatically generated from $file - do not edit */\n";
+    print "/* automatically generated from $file - do not edit */\n\n";
     $expr_regs = 1;
     printf "#define EXPR_REG_START %d\n", $expr_regs;
     print "enum reg_enum {\n";
@@ -101,7 +101,8 @@ if ( $fmt eq 'h' ) {
     print "\n";
 } elsif ( $fmt eq 'c' ) {
     # Output regs.c
-    print "/* automatically generated from $file - do not edit */\n";
+    print "/* automatically generated from $file - do not edit */\n\n";
+    print "#include \"compiler.h\"\n\n";
     print "static const char * const reg_names[] = "; $ch = '{';
     # This one has no dummy entry for 0
     foreach $reg ( sort(keys(%regs)) ) {
diff --git a/stdscan.c b/stdscan.c
index aecbd4a7..934fdf54 100644
--- a/stdscan.c
+++ b/stdscan.c
@@ -1,3 +1,5 @@
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/sync.c b/sync.c
index 562c59d6..b60d2a4a 100644
--- a/sync.c
+++ b/sync.c
@@ -6,6 +6,8 @@
  * distributed in the NASM archive.
  */
 
+#include "compiler.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <limits.h>
diff --git a/tokhash.pl b/tokhash.pl
index 2265bd0e..b5e85aaf 100755
--- a/tokhash.pl
+++ b/tokhash.pl
@@ -168,6 +168,7 @@ if ($output eq 'h') {
     print " */\n";
     print "\n";
     
+    print "#include \"compiler.h\"\n";
     print "#include <string.h>\n";
     print "#include \"nasm.h\"\n";
     print "#include \"hashtbl.h\"\n";