diff --git a/kdecore/io/karchive.cpp b/kdecore/io/karchive.cpp
index 24f98d57..e190bb9a 100644
--- a/kdecore/io/karchive.cpp
+++ b/kdecore/io/karchive.cpp
@@ -42,9 +42,7 @@
 #include <pwd.h>
 #include <assert.h>
 #include <sys/stat.h>
-#ifdef Q_OS_UNIX
 #include <limits.h>  // PATH_MAX
-#endif
 
 class KArchivePrivate
 {
diff --git a/kdecore/io/kfilesystemtype_p.cpp b/kdecore/io/kfilesystemtype_p.cpp
index e9343f9d..538f0503 100644
--- a/kdecore/io/kfilesystemtype_p.cpp
+++ b/kdecore/io/kfilesystemtype_p.cpp
@@ -57,16 +57,30 @@ KFileSystemType::Type determineFileSystemTypeImpl(const QByteArray& path)
 
 #elif defined(Q_OS_LINUX) || defined(Q_OS_HURD)
 # include <sys/vfs.h>
-# include <linux/magic.h>
 // LSB 3.2 has statfs in sys/statfs.h, sys/vfs.h is just an empty dummy header
 # include <sys/statfs.h>
-
-# ifndef AUTOFSNG_SUPER_MAGIC
-#  define AUTOFSNG_SUPER_MAGIC  0x7d92b1a0
+# if defined(Q_OS_LINUX)
+#  include <linux/magic.h>
 # endif
+
+# ifndef NFS_SUPER_MAGIC
+#  define NFS_SUPER_MAGIC       0x00006969
+# endif
+# ifndef AUTOFS_SUPER_MAGIC
+#  define AUTOFS_SUPER_MAGIC    0x00000187
+# endif
+# ifndef MSDOS_SUPER_MAGIC
+#  define MSDOS_SUPER_MAGIC     0x00004d44
+# endif
+# ifndef SMB_SUPER_MAGIC
+#  define SMB_SUPER_MAGIC       0x0000517B
+#endif
 # ifndef FUSE_SUPER_MAGIC
 #  define FUSE_SUPER_MAGIC     0x65735546
 # endif
+# ifndef RAMFS_MAGIC
+#  define RAMFS_MAGIC          0x858458F6
+# endif
 
 // Reverse-engineering without C++ code:
 // strace stat -f /mnt 2>&1|grep statfs|grep mnt, and look for f_type
diff --git a/kdecore/kernel/kstandarddirs.cpp b/kdecore/kernel/kstandarddirs.cpp
index 8d444ea5..c5589824 100644
--- a/kdecore/kernel/kstandarddirs.cpp
+++ b/kdecore/kernel/kstandarddirs.cpp
@@ -63,6 +63,10 @@
 
 #define case_sensitivity Qt::CaseSensitive
 
+#ifndef PATH_MAX
+# define PATH_MAX _POSIX_PATH_MAX
+#endif
+
 class KStandardDirs::KStandardDirsPrivate
 {
 public:
@@ -796,8 +800,8 @@ KStandardDirs::KStandardDirsPrivate::realPath(const QString &dirname)
         return dirname;
     }
 
-    char realpath_buffer[MAXPATHLEN + 1];
-    memset(realpath_buffer, 0, MAXPATHLEN + 1);
+    char realpath_buffer[PATH_MAX + 1];
+    memset(realpath_buffer, 0, PATH_MAX + 1);
 
     /* If the path contains symlinks, get the real name */
     if (realpath( QFile::encodeName(dirname).constData(), realpath_buffer) != 0) {
@@ -846,8 +850,8 @@ KStandardDirs::realPath(const QString &dirname) const
 QString
 KStandardDirs::realFilePath(const QString &filename)
 {
-    char realpath_buffer[MAXPATHLEN + 1];
-    memset(realpath_buffer, 0, MAXPATHLEN + 1);
+    char realpath_buffer[PATH_MAX + 1];
+    memset(realpath_buffer, 0, PATH_MAX + 1);
 
     /* If the path contains symlinks, get the real name */
     if (realpath( QFile::encodeName(filename).constData(), realpath_buffer) != 0) {
@@ -1355,9 +1359,9 @@ static QString readEnvPath(const char *env)
 #ifdef Q_OS_LINUX
 static QString executablePrefix()
 {
-    char path_buffer[MAXPATHLEN + 1];
-    path_buffer[MAXPATHLEN] = 0;
-    int length = readlink ("/proc/self/exe", path_buffer, MAXPATHLEN);
+    char path_buffer[PATH_MAX + 1];
+    path_buffer[PATH_MAX] = 0;
+    int length = readlink ("/proc/self/exe", path_buffer, PATH_MAX);
     if (length == -1)
         return QString();
 
diff --git a/kinit/lnusertemp.c b/kinit/lnusertemp.c
index 84dc168e..6313adb3 100644
--- a/kinit/lnusertemp.c
+++ b/kinit/lnusertemp.c
@@ -25,7 +25,6 @@
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/un.h>
-
 #include <errno.h>
 #include <string.h>
 #include <stdio.h>
@@ -36,6 +35,10 @@
 #include <limits.h>
 #endif
 
+#ifndef PATH_MAX
+# define PATH_MAX _POSIX_PATH_MAX
+#endif
+
 int check_tmp_dir(const char *tmp_dir, int check_ownership);
 int create_link(const char *file, const char *tmp_dir);
 int build_link(const char* tmp, const char *tmp_prefix, const char *kde_prefix);
diff --git a/kioslave/file/file_unix.cpp b/kioslave/file/file_unix.cpp
index ca4cf3ba..d8f64825 100644
--- a/kioslave/file/file_unix.cpp
+++ b/kioslave/file/file_unix.cpp
@@ -46,10 +46,6 @@
 #include <pwd.h>
 #include <stdlib.h>
 
-#if defined(HAVE_LIMITS_H)
-#include <limits.h>  // PATH_MAX
-#endif
-
 //sendfile has different semantics in different platforms
 #if defined HAVE_SENDFILE && defined Q_OS_LINUX
 #define USE_SENDFILE 1
diff --git a/kpty/kpty.cpp b/kpty/kpty.cpp
index 32fa553b..4a7d3358 100644
--- a/kpty/kpty.cpp
+++ b/kpty/kpty.cpp
@@ -107,11 +107,7 @@ extern "C" {
 #define TTY_GROUP "tty"
 
 #ifndef PATH_MAX
-# ifdef MAXPATHLEN
-#  define PATH_MAX MAXPATHLEN
-# else
-#  define PATH_MAX 1024
-# endif
+# define PATH_MAX _POSIX_PATH_MAX
 #endif
 
 ///////////////////////