diff --git a/src/common/mm_io.h b/src/common/mm_io.h
index 71347c1fe..b06a53083 100644
--- a/src/common/mm_io.h
+++ b/src/common/mm_io.h
@@ -33,7 +33,7 @@ using namespace libebml;
 
 class MTX_DLL_API mm_io_c: public IOCallback {
 protected:
-#if !defined(SYS_UNIX)
+#if defined(SYS_WINDOWS)
   bool _eof;
 #endif
   char *file_name;
diff --git a/src/mkvinfo.cpp b/src/mkvinfo.cpp
index b4993f9c4..b01c4dbc3 100644
--- a/src/mkvinfo.cpp
+++ b/src/mkvinfo.cpp
@@ -2538,7 +2538,7 @@ int console_main(int argc, char **argv) {
 }
 
 void setup() {
-#if defined(SYS_UNIX)
+#if !defined(COMP_MSC)
   if (setlocale(LC_CTYPE, "") == NULL)
     mxerror("Could not set the locale properly. Check the "
             "LANG, LC_ALL and LC_CTYPE environment variables.\n");
@@ -2565,7 +2565,7 @@ int main(int argc, char **argv) {
   return res;
 }
 
-#elif defined(SYS_UNIX)
+#elif defined(SYS_UNIX) || defined(SYS_APPLE)
 
 int main(int argc, char **argv) {
   char *initial_file;
diff --git a/src/mkvmerge.cpp b/src/mkvmerge.cpp
index a646aeb3d..c499ffa83 100644
--- a/src/mkvmerge.cpp
+++ b/src/mkvmerge.cpp
@@ -24,7 +24,7 @@
 
 #include <errno.h>
 #include <ctype.h>
-#if defined(SYS_UNIX) || defined(COMP_CYGWIN)
+#if defined(SYS_UNIX) || defined(COMP_CYGWIN) || defined(SYS_APPLE)
 #include <signal.h>
 #endif
 #include <stdlib.h>
@@ -426,7 +426,7 @@ static int get_type(char *filename) {
 
 // {{{ helper functions (sighandler, display_progress)
 
-#if defined(SYS_UNIX) || defined(COMP_CYGWIN)
+#if defined(SYS_UNIX) || defined(COMP_CYGWIN) || defined(SYS_APPLE)
 static void sighandler(int signum) {
 #ifdef DEBUG
   if (signum == SIGUSR1)
@@ -1935,7 +1935,7 @@ static void setup() {
             "LANG, LC_ALL and LC_CTYPE environment variables.\n");
 #endif
 
-#if defined(SYS_UNIX) || defined(COMP_CYGWIN)
+#if defined(SYS_UNIX) || defined(COMP_CYGWIN) || defined(SYS_APPLE)
   signal(SIGUSR1, sighandler);
   signal(SIGINT, sighandler);
 
diff --git a/src/mmg/mmg.cpp b/src/mmg/mmg.cpp
index 85e772190..ceb85fc73 100644
--- a/src/mmg/mmg.cpp
+++ b/src/mmg/mmg.cpp
@@ -35,7 +35,7 @@
 
 #include "chapters.h"
 #include "common.h"
-#ifdef SYS_UNIX
+#if defined(SYS_UNIX) || defined(SYS_APPLE)
 #include "matroskalogo_big.xpm"
 #endif
 #include "mmg.h"
@@ -102,7 +102,7 @@ wxString shell_escape(wxString source) {
   wxString escaped;
 
   for (i = 0; i < source.Length(); i++) {
-#ifdef SYS_UNIX
+#if defined(SYS_UNIX) || defined(SYS_APPLE)
     if (source[i] == '"')
       escaped += "\\\"";
     else if (source[i] == '\\')