diff --git a/CMakeLists.txt b/CMakeLists.txt
index 033a953..384ab38 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,6 +27,8 @@ find_package(Sqlite3)
 
 include(TestBigEndian)
 include(CheckSymbolExists) 
+include(CheckIncludeFile)
+include(CheckTypeSize)
 
 #Some functions need this to be found
 add_definitions(-D_GNU_SOURCE)
@@ -62,6 +64,11 @@ if (MSVC)
 	add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 endif()
 
+check_include_file(sys/types.h HAVE_SYS_TYPES_H)
+if (HAVE_SYS_TYPES_H)
+set (CMAKE_EXTRA_INCLUDE_FILES ${CMAKE_EXTRA_INCLUDE_FILES} "sys/types.h")
+endif()
+check_type_size( ssize_t SSIZE_T )
 check_symbol_exists(memmem string.h HAVE_MEMMEM)
 check_symbol_exists(strndup string.h HAVE_STRNDUP)
 
diff --git a/src/system.h.in b/src/system.h.in
index a946d3a..8264e2d 100644
--- a/src/system.h.in
+++ b/src/system.h.in
@@ -34,7 +34,6 @@
 #endif
 
 #if defined(__CYGWIN__) || defined(__MINGW32__)
-#define HAVE_SSIZE_T
 #define NEED_GETOPT
 #endif
 
@@ -69,6 +68,10 @@
 #include <string.h>
 #include <time.h>
 
+#cmakedefine HAVE_SYS_TYPES_H
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
 #if !defined(WIN32)
 #include <inttypes.h>
 #include <unistd.h>
@@ -77,10 +80,10 @@
 #include <sys/resource.h>
 #define HAVE_DLOPEN
 #define HAVE_GETOPT
-#define HAVE_SSIZE_T
 #include <dlfcn.h>
 #define HAVE_GETRLIMIT
 #endif
+#cmakedefine HAVE_SSIZE_T
 #cmakedefine HAVE_STRNDUP
 #cmakedefine HAVE_MEMMEM