diff --git a/CMakeLists.txt b/CMakeLists.txt
index d2167f3..f752999 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -45,5 +45,11 @@ if(${LUNAPURPURA_DEBUG})
   add_definitions(-DLUNAPURPURA_DEBUG)
 endif()
 
+include(TestBigEndian)
+test_big_endian(LUNAPURPURA_BIG_ENDIAN)
+if(${LUNAPURPURA_BIG_ENDIAN})
+  add_definitions(-DLUNAPURPURA_BIG_ENDIAN)
+endif()
+
 # Good to go.
 add_subdirectory(src)
diff --git a/src/lputil/lputil.c b/src/lputil/lputil.c
index 3a1ca5a..3c9b801 100644
--- a/src/lputil/lputil.c
+++ b/src/lputil/lputil.c
@@ -184,7 +184,9 @@ size_t
 ReadUint16(FILE *file, size_t count, uint16_t *dest)
 {
 	size_t rv = fread(dest, sizeof(uint16_t), count, file);
+#ifndef LUNAPURPURA_BIG_ENDIAN
 	*dest = htons(*dest);
+#endif
 	return rv;
 }
 
@@ -197,7 +199,9 @@ size_t
 ReadUint16LE(FILE *file, size_t count, uint16_t *dest)
 {
 	size_t rv = fread(dest, sizeof(uint16_t), count, file);
-	/* XXX do something to guarantee it was little-endian */
+#ifdef LUNAPURPURA_BIG_ENDIAN
+	*dest = ntohs(*dest);
+#endif
 	return rv;
 }
 
@@ -210,7 +214,9 @@ size_t
 ReadUint32(FILE *file, size_t count, uint32_t *dest)
 {
 	size_t rv = fread(dest, sizeof(uint32_t), count, file);
+#ifndef LUNAPURPURA_BIG_ENDIAN
 	*dest = htonl(*dest);
+#endif
 	return rv;
 }
 
@@ -223,6 +229,8 @@ size_t
 ReadUint32LE(FILE *file, size_t count, uint32_t *dest)
 {
 	size_t rv = fread(dest, sizeof(uint32_t), count, file);
-	/* XXX do something to guarantee it was little-endian */
+#ifdef LUNAPURPURA_BIG_ENDIAN
+	*dest = ntohl(*dest);
+#endif
 	return rv;
 }