diff --git a/config.h.in b/config.h.in
index 2c2fca5..1cd2156 100644
--- a/config.h.in
+++ b/config.h.in
@@ -127,6 +127,9 @@
 /* Define to 1 if you have the <sys/ioctl.h> header file. */
 #undef HAVE_SYS_IOCTL_H
 
+/* Define to 1 if you have the <sys/prctl.h> header file. */
+#undef HAVE_SYS_PRCTL_H
+
 /* Define to 1 if you have the <sys/stat.h> header file. */
 #undef HAVE_SYS_STAT_H
 
@@ -167,6 +170,9 @@
 /* Define to the one symbol short name of this package. */
 #undef PACKAGE_TARNAME
 
+/* Define to the home page for this package. */
+#undef PACKAGE_URL
+
 /* Define to the version of this package. */
 #undef PACKAGE_VERSION
 
@@ -179,6 +185,11 @@
 /* Define to 1 if your <sys/time.h> declares `struct tm'. */
 #undef TM_IN_SYS_TIME
 
+/* Enable large inode numbers on Mac OS X 10.5.  */
+#ifndef _DARWIN_USE_64_BIT_INODE
+# define _DARWIN_USE_64_BIT_INODE 1
+#endif
+
 /* Number of bits in a file offset, on hosts where this is settable. */
 #undef _FILE_OFFSET_BITS
 
diff --git a/configure b/configure
index f6c1514..8024399 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for cpm 0.27.
+# Generated by GNU Autoconf 2.69 for cpm 0.28.
 #
 # Report bugs to <kwy@redpill-linpro.com>.
 #
@@ -548,8 +548,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='cpm'
 PACKAGE_TARNAME='cpm'
-PACKAGE_VERSION='0.27'
-PACKAGE_STRING='cpm 0.27'
+PACKAGE_VERSION='0.28'
+PACKAGE_STRING='cpm 0.28'
 PACKAGE_BUGREPORT='kwy@redpill-linpro.com'
 PACKAGE_URL=''
 
@@ -1226,7 +1226,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures cpm 0.27 to adapt to many kinds of systems.
+\`configure' configures cpm 0.28 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1287,7 +1287,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of cpm 0.27:";;
+     short | recursive ) echo "Configuration of cpm 0.28:";;
    esac
   cat <<\_ACEOF
 
@@ -1392,7 +1392,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-cpm configure 0.27
+cpm configure 0.28
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -1815,7 +1815,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by cpm $as_me 0.27, which was
+It was created by cpm $as_me 0.28, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -4633,6 +4633,18 @@ fi
 
 done
 
+for ac_header in sys/prctl.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "sys/prctl.h" "ac_cv_header_sys_prctl_h" "$ac_includes_default"
+if test "x$ac_cv_header_sys_prctl_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_SYS_PRCTL_H 1
+_ACEOF
+
+fi
+
+done
+
 
 # Checks for typedefs, structures, and compiler characteristics.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking typedefs, structures, and compiler characteristics" >&5
@@ -6300,7 +6312,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by cpm $as_me 0.27, which was
+This file was extended by cpm $as_me 0.28, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -6362,7 +6374,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-cpm config.status 0.27
+cpm config.status 0.28
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.in b/configure.in
index e31403f..0f335ff 100644
--- a/configure.in
+++ b/configure.in
@@ -3,7 +3,7 @@
 
 AC_MSG_NOTICE([general setup])
 AC_PREREQ(2.59)
-AC_INIT(cpm, 0.27, kwy@redpill-linpro.com)
+AC_INIT(cpm, 0.28, kwy@redpill-linpro.com)
 AC_CONFIG_SRCDIR([config.h.in])
 AC_CONFIG_HEADER([config.h])
 
@@ -372,6 +372,7 @@ AC_SUBST(LIBGPGME_CFLAGS)
 AC_MSG_NOTICE([checking header files])
 AC_HEADER_STDC
 AC_CHECK_HEADERS([fcntl.h getopt.h libintl.h locale.h stdlib.h sys/fsuid.h sys/ioctl.h termios.h])
+AC_CHECK_HEADERS(sys/prctl.h)
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_MSG_NOTICE([checking typedefs, structures, and compiler characteristics])
diff --git a/cpm.h b/cpm.h
index a946d0b..7bc13cc 100644
--- a/cpm.h
+++ b/cpm.h
@@ -30,6 +30,12 @@
 #include "config.h"
 #define _GNU_SOURCE
 
+#ifdef HAVE_STDLIB_H
+  #ifndef _SVID_SOURCE
+   #define _SVID_SOURCE
+  #endif
+  #include <stdlib.h>
+#endif
 #include <errno.h>
 #ifdef HAVE_FCNTL_H
   #include <fcntl.h>
@@ -43,9 +49,6 @@
 #endif
 #include <signal.h>
 #include <stdio.h>
-#ifdef HAVE_STDLIB_H
-  #include <stdlib.h>
-#endif
 #ifdef HAVE_STRINGS_H
   #include <string.h>
 #endif
diff --git a/interface_gui.c b/interface_gui.c
index 638c692..9739879 100644
--- a/interface_gui.c
+++ b/interface_gui.c
@@ -432,6 +432,7 @@ int getInfodataLength(void)
         return max_x;
     else
         return STDBUFFERLENGTH;
+    (void)max_y; // remove unused var warning
   }
 
 
@@ -1337,6 +1338,7 @@ int guiDialogHandleKeys(EObjectType cdktype, void* object, void* clientdata,
     while (!done);
 
     return 1;
+    (void) selection; // unused
   }
 
 
diff --git a/interface_xml.c b/interface_xml.c
index a4a8779..87dfdfd 100644
--- a/interface_xml.c
+++ b/interface_xml.c
@@ -383,7 +383,6 @@ void initXMLInterface(void)
 xmlNode* nodeFind(char* label)
   {
     xmlNode*            curnode;
-    xmlNode*            newnode;
     char*               prop;
 
     TRACE(99, "nodeFind()", NULL);
@@ -392,7 +391,6 @@ xmlNode* nodeFind(char* label)
       { return 0; }
 
     curnode = xmlwalklist[level - 1] -> children;
-    newnode = NULL;
     while (curnode)
       {
         if (curnode -> type == XML_ELEMENT_NODE &&
diff --git a/memory.c b/memory.c
index 5ae7960..b21c361 100644
--- a/memory.c
+++ b/memory.c
@@ -44,7 +44,7 @@ long int                memorycounter = 0;
  */
 void* memDebugAlloc(const char* file, int line, size_t size)
   {
-    fprintf(stderr, "alloc  %5d (%s, line %d)\n", size, file, line);
+    fprintf(stderr, "alloc  %5lu (%s, line %d)\n", size, file, line);
     return memRealAlloc(size);
   }
 
@@ -59,7 +59,7 @@ void* memDebugAlloc(const char* file, int line, size_t size)
  */
 void memDebugFree(const char* file, int line, void* ptr, size_t size)
   {
-    fprintf(stderr, "free   %5d (%s, line %d)\n", size, file, line);
+    fprintf(stderr, "free   %5lu (%s, line %d)\n", size, file, line);
     memRealFree(ptr, size);
   }
 
@@ -76,7 +76,7 @@ void memDebugFreeString(const char* file, int line, void* ptr)
   {
     if (ptr)
       {
-        fprintf(stderr, "free   %5d (%s, line %d)\n",
+        fprintf(stderr, "free   %5zd (%s, line %d)\n",
             strlen(ptr) + 1, file, line);
       }
 
@@ -118,7 +118,7 @@ void* memRealAlloc(size_t size)
     ptr = malloc(size);
     if (!ptr)
       {
-        fprintf(stderr, _("out of memory error - tried to allocate %d byte.\n"),
+        fprintf(stderr, _("out of memory error - tried to allocate %lu byte.\n"),
             size);
         exit(1);
       }
@@ -200,7 +200,7 @@ void* memRealRealloc(void* ptr, size_t size_old, size_t size_new)
     if (!ptr)
       {
         fprintf(stderr,
-            _("out of memory error - tried to reallocate %d byte.\n"),
+            _("out of memory error - tried to reallocate %lu byte.\n"),
             size_new);
         exit(1);
       }
diff --git a/security.c b/security.c
index 693f396..4735636 100644
--- a/security.c
+++ b/security.c
@@ -24,10 +24,13 @@
 /* #############################################################################
  * includes
  */
-#include <sys/utsname.h>
+
 #include "cpm.h"
+#include <sys/utsname.h>
+#if defined(HAVE_SYS_PRCTL_H)
 #include <sys/ptrace.h>
 #include <sys/prctl.h>
+#endif
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <regex.h>
@@ -495,7 +498,7 @@ int initSecurity(int* max_mem_lock, int* memory_safe, int* ptrace_safe,
     *memory_safe = 0;
     *ptrace_safe = 0;
 
-#ifdef _SYS_PTRACE_H
+#if defined(_SYS_PTRACE_H) && !defined(TRACE_DEBUG)
     /* Try to fork a child which then ptrace attaches to it's parent
      * This will safely prevent other processes (even root) to be able to attach to us */
     {
@@ -510,20 +513,22 @@ int initSecurity(int* max_mem_lock, int* memory_safe, int* ptrace_safe,
        }
 
        if (p == 0) {
+#if defined(HAVE_SYS_PRCTL_H)
            // makes the child unattachable
            if (prctl(PR_SET_DUMPABLE, 0, 0, 0, 0) != 0) {
                fprintf(stderr, "Can not set child non dumpable\n");
                _exit(1);
            }
+#endif
 
-           if (ptrace(PTRACE_ATTACH, p0, 0, 0) != 0) {
+           if (ptrace(PT_ATTACH, p0, 0, 0) != 0) {
                // someone is already attached to us; shoot the parent in the head
                fprintf(stderr, "Can't attach to parent!\n");
                kill(p0, SIGKILL);
                _exit(1);
            }
            while (1) {
-               if(ptrace(PTRACE_SYSCALL, p0, 0, 0) == 0)
+               if(ptrace(PT_SYSCALL, p0, 0, 0) == 0)
                    waitpid(p0, &status, 0);
                if(errno == ESRCH && kill(p0, 0) == -1)
                    exit(0); // parent is dead
@@ -711,10 +716,9 @@ int initSecurity(int* max_mem_lock, int* memory_safe, int* ptrace_safe,
     /* NOTE: no file must be opened before this test! */
     canary = dup(0);
     close(canary);
-    if (canary != 3)
+    if (canary < 3)
       {
-        fprintf(stderr, "%s\n",
-            _("stdin, stdout and/or stderr are invalid."));
+        fprintf(stderr, "%s\n", _("stdin, stdout and/or stderr are invalid."));
         return 1;
       }
 
diff --git a/tests/encrypt-result.txt b/tests/encrypt-result.txt
index 60656c3..a19791c 100644
--- a/tests/encrypt-result.txt
+++ b/tests/encrypt-result.txt
@@ -38,4 +38,4 @@
 <!ATTLIST user uid CDATA #REQUIRED>
 <!ATTLIST user created-on CDATA #REQUIRED>
 ]>
-<root version="0.25beta2"><editor><user uid="1">unknown</user></editor><template/></root>
+<root version="0.28"><editor><user uid="1">unknown</user></editor><template/></root>