diff --git a/src/UDPConnection.cpp b/src/UDPConnection.cpp
index 0829ed2..b498088 100644
--- a/src/UDPConnection.cpp
+++ b/src/UDPConnection.cpp
@@ -3058,7 +3058,7 @@ UDPC_IPV6_ADDR_TYPE UDPC_a4toa6(uint32_t a4_be) {
 
     uint32_t a4 = ntohl(a4_be);
 
-    if(a4 == 0x7F000001) {
+    if(a4 == 0x0100007F) {
         return in6addr_loopback;
     }
 
diff --git a/src/test/TestUDPC.cpp b/src/test/TestUDPC.cpp
index e0e0f76..a8d1ddc 100644
--- a/src/test/TestUDPC.cpp
+++ b/src/test/TestUDPC.cpp
@@ -321,7 +321,7 @@ TEST(UDPC, NetworkOrderEndianness) {
 
 TEST(UDPC, a4toa6) {
     EXPECT_EQ(UDPC_a4toa6(0), in6addr_any);
-    uint32_t a4 = htonl(0x7F000001);
+    uint32_t a4 = htonl(0x0100007F);
     EXPECT_EQ(UDPC_a4toa6(a4), in6addr_loopback);
 
     UDPC_IPV6_ADDR_TYPE a6 = UDPC_strtoa("::FFFF:0102:0304");