diff --git a/src/compat/internal.h b/src/compat/internal.h
index 47d32cd..d1c342c 100644
--- a/src/compat/internal.h
+++ b/src/compat/internal.h
@@ -33,14 +33,16 @@
 
 #  if defined(__MINGW32__) || defined(__MINGW64__)
 
-#  include "off_t.h"
+#   if defined(__STRICT_ANSI__) || defined(MINGW_DEFINE_OFF_T)
+#    include "off_t.h"
 
-#   if !defined(__MINGW64__)
-#    define off_t cr_off32
-#   else
-#    define off_t cr_off64
+#    if !defined(__MINGW64__)
+#     define off_t cr_off32
+#    else
+#     define off_t cr_off64
+#    endif
+#    define off64_t cr_off64
 #   endif
-#   define off64_t cr_off64
 #  endif
 #  include <io.h>
 #  if defined(__MINGW32__) || defined(__MINGW64__)
diff --git a/src/compat/off_t.h b/src/compat/off_t.h
index 24dc65d..5918cea 100644
--- a/src/compat/off_t.h
+++ b/src/compat/off_t.h
@@ -1,9 +1,32 @@
-#ifndef OFF_T_H_
-# define OFF_T_H_
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright © 2015 Franklin "Snaipe" Mathieu <http://snai.pe/>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef CR_OFF_T_DEFINED
+# define CR_OFF_T_DEFINED
 
 # include <stdint.h>
 
 typedef int32_t cr_off32;
 typedef int64_t cr_off64;
 
-#endif /* !OFF_T_H_ */
+#endif /* !CR_OFF_T_DEFINED */
diff --git a/src/compat/posix.h b/src/compat/posix.h
index 81af6b3..0a7bbda 100644
--- a/src/compat/posix.h
+++ b/src/compat/posix.h
@@ -42,14 +42,16 @@
 # endif
 # if defined(__MINGW32__) || defined(__MINGW64__)
 
-# include "off_t.h"
+#  if defined(__STRICT_ANSI__) || defined(MINGW_DEFINE_OFF_T)
+#   include "off_t.h"
 
-#  if !defined(__MINGW64__)
-#   define off_t cr_off32
-#  else
-#   define off_t cr_off64
+#   if !defined(__MINGW64__)
+#    define off_t cr_off32
+#   else
+#    define off_t cr_off64
+#   endif
+#   define off64_t cr_off64
 #  endif
-#  define off64_t cr_off64
 # endif
 # include <stdio.h>
 # include <string.h>