--- squashfs-tools/mksquashfs.c
+++ squashfs-tools/mksquashfs.c
@@ -48,6 +48,9 @@
 #include <math.h>
 #include <regex.h>
 #include <fnmatch.h>
+#if !defined(FNM_EXTMATCH) // GNU_EXTENSION
+#define FNM_EXTMATCH 0
+#endif
 
 #ifndef linux
 #define __BYTE_ORDER BYTE_ORDER
--- squashfs-tools/unsquashfs.c
+++ squashfs-tools/unsquashfs.c
@@ -42,6 +42,9 @@
 #include <time.h>
 #include <regex.h>
 #include <fnmatch.h>
+#if !defined(FNM_EXTMATCH) // GNU_EXTENSION
+#define FNM_EXTMATCH 0
+#endif
 #include <signal.h>
 #include <pthread.h>
 #include <math.h>