diff --git a/include/osmocom/core/endian.h b/include/osmocom/core/endian.h
new file mode 100644
index 0000000..c890fd7
--- /dev/null
+++ b/include/osmocom/core/endian.h
@@ -0,0 +1,38 @@
+#pragma once
+
+/**
+ * GNU and FreeBSD have various ways to express the
+ * endianess but none of them is similiar enough. This
+ * will create two defines that allows to decide on the
+ * endian. The following will be defined to either 0 or
+ * 1 at the end of the file.
+ *
+ *      OSMO_IS_LITTLE_ENDIAN
+ *      OSMO_IS_BIG_ENDIAN
+ *
+ */
+
+#if defined(__FreeBSD__)
+#include <sys/endian.h>
+        #if BYTE_ORDER == LITTLE_ENDIAN
+                #define OSMO_IS_LITTLE_ENDIAN           1
+                #define OSMO_IS_BIG_ENDIAN              0
+        #elif BYTE_ORDER == BIG_ENDIAN
+                #define OSMO_IS_LITTLE_ENDIAN           0
+                #define OSMO_IS_BIG_ENDIAN              1
+        #else
+                #error "Unknown endian"
+        #endif
+#else
+#include <endian.h>
+        #if __BYTE_ORDER == __LITTLE_ENDIAN
+                #define OSMO_IS_LITTLE_ENDIAN           1
+                #define OSMO_IS_BIG_ENDIAN              0
+        #elif __BYTE_ORDER == __BIG_ENDIAN
+                #define OSMO_IS_LITTLE_ENDIAN           0
+                #define OSMO_IS_BIG_ENDIAN              1
+        #else
+                #error "Unknown endian"
+        #endif
+#endif
+