diff --git a/src/build/util.c b/src/build/util.c
index aacf33927..012c557da 100644
--- a/src/build/util.c
+++ b/src/build/util.c
@@ -19,11 +19,12 @@
 #include <util/goodies.c>
 #include <util/language.c>
 #include <util/lists.c>
-#include <util/quicklist.c>
 #include <util/log.c>
 #include <util/message.c>
 #include <util/nrmessage.c>
+#include <util/os.c>
 #include <util/parser.c>
+#include <util/quicklist.c>
 #include <util/rand.c>
 #include <util/resolve.c>
 #include <util/sql.c>
diff --git a/src/gamecode/study.c b/src/gamecode/study.c
index 36fda0217..2fbcb270e 100644
--- a/src/gamecode/study.c
+++ b/src/gamecode/study.c
@@ -589,7 +589,7 @@ learn_cmd(unit * u, order * ord)
     struct building * b = inside_building(u);
     const struct building_type * btype = b?b->type:NULL;
 
-    if (btype == bt_find("academy")) {
+    if (btype && btype == bt_find("academy")) {
       studycost = MAX(50, studycost * 2);
     }
   }
diff --git a/src/kernel/battle.c b/src/kernel/battle.c
index 0aaa0e840..3d8747c61 100644
--- a/src/kernel/battle.c
+++ b/src/kernel/battle.c
@@ -59,6 +59,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <util/cvector.h>
 #include <util/language.h>
 #include <util/log.h>
+#include <util/os.h>
 #include <util/parser.h>
 #include <util/rand.h>
 #include <util/rng.h>
@@ -3575,7 +3576,7 @@ make_battle(region * r)
     char zText[MAX_PATH];
     char zFilename[MAX_PATH];
     sprintf(zText, "%s/battles", basepath());
-    makedir(zText, 0700);
+    os_mkdir(zText, 0700);
     sprintf(zFilename, "%s/battle-%d-%s.log", zText, obs_count, simplename(r));
     bdebug = fopen(zFilename, "w");
     if (!bdebug) log_error(("battles cannot be debugged\n"));
diff --git a/src/kernel/reports.c b/src/kernel/reports.c
index c22c5f392..0cca313b4 100644
--- a/src/kernel/reports.c
+++ b/src/kernel/reports.c
@@ -51,6 +51,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <util/language.h>
 #include <util/lists.h>
 #include <util/log.h>
+#include <util/os.h>
 #include <util/quicklist.h>
 
 /* libc includes */
@@ -1491,7 +1492,7 @@ init_reports(void)
     if (stat(reportpath(), &st)==0) return 0;
   }
 #endif
-  if (makedir(reportpath(), 0700)!=0) {
+  if (os_mkdir(reportpath(), 0700)!=0) {
     if (errno!=EEXIST) {
       perror("could not create reportpath");
       return -1;
diff --git a/src/kernel/save.c b/src/kernel/save.c
index 17a17b685..7dedc93b1 100644
--- a/src/kernel/save.c
+++ b/src/kernel/save.c
@@ -61,6 +61,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <util/language.h>
 #include <util/lists.h>
 #include <util/log.h>
+#include <util/os.h>
 #include <util/parser.h>
 #include <util/quicklist.h>
 #include <util/rand.h>
@@ -1683,7 +1684,11 @@ writegame(const char *filename, int mode)
 
   store->encoding = enc_gamedata;
   if (store->open(store, path, IO_WRITE)!=0) {
-    return -1;
+    int err = os_mkdir(datapath(), 0700);
+    if (err) return err;
+    if (store->open(store, path, IO_WRITE)!=0) {
+      return -1;
+    }
   }
 
   /* globale Variablen */
diff --git a/src/platform.h b/src/platform.h
index e8b988885..96903dde7 100644
--- a/src/platform.h
+++ b/src/platform.h
@@ -120,19 +120,12 @@ typedef struct stat stat_type;
 # define HAVE_SNPRINTF
 #ifdef _POSIX_SOURCE /* MINGW doesn't seem to have these */
 # define HAVE_EXECINFO
-# define HAVE_MKDIR_WITH_PERMISSION
 # define HAVE_SIGACTION
 # define HAVE_LINK
 # define HAVE_SLEEP
 #endif
 #endif
 
-/* egcpp 4 dos */
-#ifdef MSDOS
-# include <dir.h>
-# define HAVE_MKDIR_WITH_PERMISSION
-#endif
-
 /* TinyCC */
 #ifdef TINYCC
 # undef HAVE_INLINE
@@ -211,15 +204,6 @@ typedef struct _stat stat_type;
 # endif
 #endif
 
-#ifdef HAVE_MKDIR_WITH_PERMISSION
-# define makedir(d, p) mkdir(d, p)
-#elif defined(HAVE_MKDIR_WITHOUT_PERMISSION)
-# define makedir(d, p) mkdir(d)
-#elif defined(HAVE__MKDIR_WITHOUT_PERMISSION)
-_CRTIMP int __cdecl _mkdir(const char *);
-# define makedir(d, p) _mkdir(d)
-#endif
-
 #ifndef HAVE_STRDUP
 extern char * strdup(const char *s);
 #endif
diff --git a/src/util.vcxproj b/src/util.vcxproj
index 02c556a66..027e10ae6 100644
--- a/src/util.vcxproj
+++ b/src/util.vcxproj
@@ -107,6 +107,7 @@
     <ClInclude Include="util\message.h" />
     <ClInclude Include="util\nrmessage.h" />
     <ClInclude Include="util\nrmessage_struct.h" />
+    <ClInclude Include="util\os.h" />
     <ClInclude Include="util\parser.h" />
     <ClInclude Include="util\patricia.h" />
     <ClInclude Include="util\quicklist.h" />
@@ -142,6 +143,7 @@
     <ClCompile Include="util\log.c" />
     <ClCompile Include="util\message.c" />
     <ClCompile Include="util\nrmessage.c" />
+    <ClCompile Include="util\os.c" />
     <ClCompile Include="util\parser.c" />
     <ClCompile Include="util\patricia.c" />
     <ClCompile Include="util\quicklist.c" />
diff --git a/src/util.vcxproj.filters b/src/util.vcxproj.filters
index 726f4856e..f1e5a7d17 100644
--- a/src/util.vcxproj.filters
+++ b/src/util.vcxproj.filters
@@ -110,6 +110,9 @@
     <ClInclude Include="util\quicklist.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="util\os.h">
+      <Filter>Source Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="util\argstack.c">
@@ -208,5 +211,8 @@
     <ClCompile Include="util\quicklist_test.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="util\os.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/src/util/os.c b/src/util/os.c
new file mode 100644
index 000000000..6360869d0
--- /dev/null
+++ b/src/util/os.c
@@ -0,0 +1,17 @@
+#include "os.h"
+
+#if defined(WIN32)
+#include <direct.h>
+#elif defined(__GCC__)
+#include <sys/stat.h>
+#endif
+
+int os_mkdir(const char * path, int mode)
+{
+#ifdef WIN32
+  mode = mode;
+  return _mkdir(path);
+#else /* POSIX is our last hope */
+  return mkdir(path, (mode_t)mode);
+#endif
+}
\ No newline at end of file
diff --git a/src/util/os.h b/src/util/os.h
new file mode 100644
index 000000000..64e17e5e9
--- /dev/null
+++ b/src/util/os.h
@@ -0,0 +1,29 @@
+/*
+Copyright (c) 1998-2010, Enno Rehling <enno@eressea.de>
+                         Katja Zedel <katze@felidae.kn-bremen.de
+                         Christian Schlittchen <corwin@amber.kn-bremen.de>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+**/
+
+#ifndef _OS_H
+#define _OS_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+  extern int os_mkdir(const char * path, int mode);
+#ifdef __cplusplus
+}
+#endif
+#endif