diff --git a/config.mak.uname b/config.mak.uname
index 82d549e48b..7d31fad241 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -198,6 +198,13 @@ ifeq ($(uname_S),OpenBSD)
 	BASIC_LDFLAGS += -L/usr/local/lib
 	HAVE_PATHS_H = YesPlease
 endif
+ifeq ($(uname_S),MirBSD)
+	NO_STRCASESTR = YesPlease
+	NO_MEMMEM = YesPlease
+	USE_ST_TIMESPEC = YesPlease
+	NEEDS_LIBICONV = YesPlease
+	HAVE_PATHS_H = YesPlease
+endif
 ifeq ($(uname_S),NetBSD)
 	ifeq ($(shell expr "$(uname_R)" : '[01]\.'),2)
 		NEEDS_LIBICONV = YesPlease
diff --git a/git-compat-util.h b/git-compat-util.h
index 7776f126d3..9e202dde78 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -75,7 +75,7 @@
 # endif
 #elif !defined(__APPLE__) && !defined(__FreeBSD__) && !defined(__USLC__) && \
       !defined(_M_UNIX) && !defined(__sgi) && !defined(__DragonFly__) && \
-      !defined(__TANDEM) && !defined(__QNX__)
+      !defined(__TANDEM) && !defined(__QNX__) && !defined(__MirBSD__)
 #define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
 #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
 #endif