diff --git a/src/bind_faction.c b/src/bind_faction.c
index 36da798c1..2ace2ae52 100644
--- a/src/bind_faction.c
+++ b/src/bind_faction.c
@@ -36,6 +36,7 @@ without prior permission by the authors of Eressea.
 
 #include <tolua.h>
 #include <string.h>
+#include <stdbool.h>
 
 typedef struct helpmode {
     const char *name;
diff --git a/src/kernel/alliance.h b/src/kernel/alliance.h
index 907fc65f7..4be05b871 100644
--- a/src/kernel/alliance.h
+++ b/src/kernel/alliance.h
@@ -18,6 +18,9 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 #ifndef H_KRNL_ALLIANCE
 #define H_KRNL_ALLIANCE
+
+#include <stdbool.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/src/kernel/order.h b/src/kernel/order.h
index 69cf1ea33..7f4b00a5e 100644
--- a/src/kernel/order.h
+++ b/src/kernel/order.h
@@ -15,6 +15,7 @@
 
 #include "keyword.h"
 #include <stddef.h>
+#include <stdbool.h>
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/keyword.h b/src/keyword.h
index e60d0731f..1d8f04bb2 100644
--- a/src/keyword.h
+++ b/src/keyword.h
@@ -2,6 +2,8 @@
 #define H_KEYWORD_H
 
 #include "kernel/types.h"
+#include <stdbool.h>
+
 #ifdef __cplusplus
 extern "C"
 {
diff --git a/src/platform.h b/src/platform.h
index 2f114cec5..7f82f46a8 100644
--- a/src/platform.h
+++ b/src/platform.h
@@ -3,6 +3,8 @@
 #ifndef UNILIB_H
 #define UNILIB_H
 
+#define _POSIX_C_SOURCE 200809L
+
 #ifndef MAX_PATH
 # define MAX_PATH 4096
 #endif
@@ -12,4 +14,5 @@
 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
 
+#define TOLUA_CAST (char*)
 #endif
diff --git a/src/util/filereader.c b/src/util/filereader.c
index 3223ca2ab..d36d3ca71 100644
--- a/src/util/filereader.c
+++ b/src/util/filereader.c
@@ -4,6 +4,7 @@
 #include <util/log.h>
 #include <util/unicode.h>
 
+#include <stdbool.h>
 #include <ctype.h>
 #include <wctype.h>
 
@@ -30,7 +31,7 @@ static int eatwhite(const char *ptr, size_t * total_size)
         ret = unicode_utf8_to_ucs4(&ucs, ptr, &size);
         if (ret != 0)
             break;
-        if (!iswxspace((wint_t)ucs))
+        if (!iswspace((wint_t)ucs))
             break;
         *total_size += size;
         ptr += size;
@@ -52,7 +53,7 @@ static const char *getbuf_latin1(FILE * F)
 
         if (bp == NULL)
             return NULL;
-        while (*bp && isxspace(*(unsigned char *)bp))
+        while (*bp && isspace(*(unsigned char *)bp))
             ++bp;                     /* eatwhite */
 
         comment = (bool)(comment && cont);
@@ -113,15 +114,15 @@ static const char *getbuf_latin1(FILE * F)
 
             if (iscntrl(c)) {
                 if (!comment && cp < fbuf + MAXLINE) {
-                    *cp++ = isxspace(c) ? ' ' : '?';
+                    *cp++ = isspace(c) ? ' ' : '?';
                 }
                 ++bp;
                 continue;
             }
-            else if (isxspace(c)) {
+            else if (isspace(c)) {
                 if (!quote) {
                     ++bp;
-                    while (*bp && isxspace(*(unsigned char *)bp))
+                    while (*bp && isspace(*(unsigned char *)bp))
                         ++bp;               /* eatwhite */
                     if (!comment && *bp && *bp != COMMENT_CHAR && cp < fbuf + MAXLINE)
                         *(cp++) = ' ';
@@ -136,7 +137,7 @@ static const char *getbuf_latin1(FILE * F)
             }
             else if (c == CONTINUE_CHAR) {
                 const char *end = ++bp;
-                while (*end && isxspace(*(unsigned char *)end))
+                while (*end && isspace(*(unsigned char *)end))
                     ++end;                /* eatwhite */
                 if (*end == '\0') {
                     bp = end;
@@ -269,7 +270,7 @@ static const char *getbuf_utf8(FILE * F)
                 break;
             }
 
-            if (iswxspace((wint_t)ucs)) {
+            if (iswspace((wint_t)ucs)) {
                 if (!quote) {
                     bp += size;
                     ret = eatwhite(bp, &size);
diff --git a/src/util/parser.c b/src/util/parser.c
index 0fbde6769..bbdb5ac7e 100644
--- a/src/util/parser.c
+++ b/src/util/parser.c
@@ -32,7 +32,7 @@ static int eatwhitespace_c(const char **str_p)
     for (;;) {
         unsigned char utf8_character = (unsigned char)*str;
         if (~utf8_character & 0x80) {
-            if (!iswxspace(utf8_character))
+            if (!iswspace(utf8_character))
                 break;
             ++str;
         }
@@ -42,7 +42,7 @@ static int eatwhitespace_c(const char **str_p)
                 log_warning("illegal character sequence in UTF8 string: %s\n", str);
                 break;
             }
-            if (!iswxspace((wint_t)ucs))
+            if (!iswspace((wint_t)ucs))
                 break;
             str += len;
         }
@@ -106,7 +106,7 @@ void skip_token(void)
                 log_warning("illegal character sequence in UTF8 string: %s\n", states->current_token);
             }
         }
-        if (iswxspace((wint_t)ucs) && quotechar == 0) {
+        if (iswspace((wint_t)ucs) && quotechar == 0) {
             return;
         }
         else {
@@ -163,7 +163,7 @@ char *parse_token(const char **str, char *lbuf, size_t buflen)
             copy = true;
             escape = false;
         }
-        else if (iswxspace((wint_t)ucs)) {
+        else if (iswspace((wint_t)ucs)) {
             if (quotechar == 0)
                 break;
             copy = true;
diff --git a/src/util/parser.h b/src/util/parser.h
index 802fc56cb..0c8306931 100644
--- a/src/util/parser.h
+++ b/src/util/parser.h
@@ -12,6 +12,7 @@
 #define UTIL_PARSER_H
 
 #include <stddef.h>
+#include <stdbool.h>
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/util/password.h b/src/util/password.h
index e1d49fb6d..b83d544a6 100644
--- a/src/util/password.h
+++ b/src/util/password.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <stdbool.h>
 #define PASSWORD_PLAINTEXT 0
 #define PASSWORD_DEFAULT PASSWORD_PLAINTEXT
 
diff --git a/src/util/rand.h b/src/util/rand.h
index 9fb3f2f69..e9d9062b7 100644
--- a/src/util/rand.h
+++ b/src/util/rand.h
@@ -1,3 +1,4 @@
+#pragma once
 /*
 Copyright (c) 1998-2015, Enno Rehling <enno@eressea.de>
 Katja Zedel <katze@felidae.kn-bremen.de
@@ -18,6 +19,9 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 #ifndef RAND_H
 #define RAND_H
+
+#include <stdbool.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/src/util/translation.c b/src/util/translation.c
index b0933d322..c733cc272 100644
--- a/src/util/translation.c
+++ b/src/util/translation.c
@@ -21,6 +21,7 @@
  /* libc includes */
 #include <ctype.h>
 #include <string.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <stdarg.h>