diff --git a/macros.pl b/macros.pl
index 4fe775ea..b1970cf5 100755
--- a/macros.pl
+++ b/macros.pl
@@ -26,7 +26,7 @@ sub charcify(@) {
     foreach $o (unpack("C*", join('',@_))) {
 	$c = pack("C", $o);
 	if ($o < 32 || $o > 126 || $c eq '"' || $c eq "\\") {
-	    $l .= sprintf("(char)%3d,", $o);
+	    $l .= sprintf("%3d,", $o);
 	} else {
 	    $l .= "\'".$c."\',";
 	}
@@ -48,7 +48,7 @@ print OUT "#include \"tables.h\"\n";
 print OUT "#include \"nasmlib.h\"\n";
 print OUT "#include \"hashtbl.h\"\n";
 print OUT "\n";
-print OUT "const char nasm_stdmac[] = {";
+print OUT "const unsigned char nasm_stdmac[] = {";
 
 my $npkg = 0;
 my @pkg_list   = ();
@@ -73,7 +73,7 @@ foreach $fname ( @ARGV ) {
 	    printf OUT "        /* %4d */ 0\n", $index++;
 	    print OUT "};\n";
 	    $index = 0;
-	    printf OUT "const char %s_stdmac[] = {\n", $out_alias[0];
+	    printf OUT "const unsigned char %s_stdmac[] = {\n", $out_alias[0];
 	    print  OUT "    /* From $fname */\n";
 	    $lastname = $fname;
 	    push(@out_list, $out_alias[0]);
@@ -86,7 +86,7 @@ foreach $fname ( @ARGV ) {
 	    printf OUT "        /* %4d */ 0\n", $index++;
 	    print OUT "};\n";
 	    $index = 0;
-	    printf OUT "static const char nasm_stdmac_%s[] = {\n", $pkg;
+	    printf OUT "static const unsigned char nasm_stdmac_%s[] = {\n", $pkg;
 	    print  OUT "    /* From $fname */\n";
 	    $lastname = $fname;
 	    push(@pkg_list, $pkg);
@@ -127,7 +127,7 @@ foreach $fname ( @ARGV ) {
     close(INPUT);
 }
 printf OUT "        /* %4d */ 0\n};\n\n", $index++;
-print OUT "const char * const nasm_stdmac_after_tasm = ",
+print OUT "const unsigned char * const nasm_stdmac_after_tasm = ",
     "&nasm_stdmac[$tasm_count];\n\n";
 
 my @hashinfo = gen_perfect_hash(\%pkg_number);
@@ -139,11 +139,11 @@ verify_hash_table(\%pkg_number, \@hashinfo);
 my ($n, $sv, $g) = @hashinfo;
 die if ($n & ($n-1));
 
-print OUT "const char *nasm_stdmac_find_package(const char *package)\n";
+print OUT "const unsigned char *nasm_stdmac_find_package(const char *package)\n";
 print OUT "{\n";
 print OUT "    static const struct {\n";
 print OUT "         const char *package;\n";
-print OUT "         const char *macros;\n";
+print OUT "         const unsigned char *macros;\n";
 print OUT "    } packages[$npkg] = {\n";
 foreach $pkg (@pkg_list) {
     printf OUT "        { \"%s\", nasm_stdmac_%s },\n",
diff --git a/preproc.c b/preproc.c
index b4eb54c6..8415ac05 100644
--- a/preproc.c
+++ b/preproc.c
@@ -642,7 +642,7 @@ static char *read_line(void)
 
     if (stdmacpos) {
 	unsigned char c;
-	const char *p = stdmacpos;
+	const unsigned char *p = stdmacpos;
 	char *ret, *q;
 	size_t len = 0;
 	while ((c = *p++)) {
@@ -2153,7 +2153,7 @@ static int do_directive(Token * tline)
 
     case PP_USE:
     {
-	static const char *use_pkg;
+	static const macros_t *use_pkg;
 	const char *pkg_macro;
 
 	t = tline->next = expand_smacro(tline->next);
@@ -2175,7 +2175,7 @@ static int do_directive(Token * tline)
 	if (!use_pkg)
 	    error(ERR_NONFATAL, "unknown `%%use' package: %s", t->text);
 	/* The first string will be <%define>__USE_*__ */
-	pkg_macro = use_pkg + 1;
+	pkg_macro = (char *)use_pkg + 1;
 	if (!smacro_defined(NULL, pkg_macro, 0, NULL, true)) {
 	    /* Not already included, go ahead and include it */
 	    stdmacpos = use_pkg;
diff --git a/preproc.h b/preproc.h
index a0f1a70a..ff1e371a 100644
--- a/preproc.h
+++ b/preproc.h
@@ -15,7 +15,7 @@ extern const char * const pp_directives[];
 extern const uint8_t pp_directives_len[];
 
 /* Pointer to a macro chain */
-typedef const char macros_t;
+typedef const unsigned char macros_t;
 
 enum preproc_token pp_token_hash(const char *token);
 void pp_include_path(char *);
diff --git a/tables.h b/tables.h
index f0044a50..b71d586b 100644
--- a/tables.h
+++ b/tables.h
@@ -14,9 +14,9 @@
 /* --- From standard.mac via macros.pl: --- */
 
 /* macros.c */
-extern const char nasm_stdmac[];
-extern const char * const nasm_stdmac_after_tasm;
-const char *nasm_stdmac_find_package(const char *);
+extern const unsigned char nasm_stdmac[];
+extern const unsigned char * const nasm_stdmac_after_tasm;
+const unsigned char *nasm_stdmac_find_package(const char *);
 
 /* --- From insns.dat via insns.pl: --- */