diff --git a/fs/reiserfs/reiserfs.h b/fs/reiserfs/reiserfs.h
index f8adaee537c2a39283bc8c4c672f0949fd79d0f4..66a2e832fa8dda5786eb0953c848c2ff1096774e 100644
--- a/fs/reiserfs/reiserfs.h
+++ b/fs/reiserfs/reiserfs.h
@@ -1958,7 +1958,9 @@ struct treepath var = {.path_length = ILLEGAL_PATH_ELEMENT_OFFSET, .reada = 0,}
 #define MAX_US_INT 0xffff
 
 // reiserfs version 2 has max offset 60 bits. Version 1 - 32 bit offset
+#ifndef U32_MAX
 #define U32_MAX (~(__u32)0)
+#endif /* !U32_MAX */
 
 static inline loff_t max_reiserfs_offset(struct inode *inode)
 {
diff --git a/include/linux/ceph/decode.h b/include/linux/ceph/decode.h
index 0442c3d800f0f9c8a9268a93715cfe2bc18c639b..27fe66a279b1e5aadb8b84e52973882df5cb25e3 100644
--- a/include/linux/ceph/decode.h
+++ b/include/linux/ceph/decode.h
@@ -10,6 +10,7 @@
 
 /* This seemed to be the easiest place to define these */
 
+#ifndef U32_MAX
 #define	U8_MAX	((u8)(~0U))
 #define	U16_MAX	((u16)(~0U))
 #define	U32_MAX	((u32)(~0U))
@@ -24,6 +25,7 @@
 #define	S16_MIN	((s16)(-S16_MAX - 1))
 #define	S32_MIN	((s32)(-S32_MAX - 1))
 #define	S64_MIN	((s64)(-S64_MAX - 1LL))
+#endif /* !U32_MAX */
 
 /*
  * in all cases,
diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c
index 8a520996f3d268b6a3a1407fce986c3cf781a871..f43947235b350baf3c2d6f42228befc95ea36e06 100644
--- a/net/ipv4/tcp_illinois.c
+++ b/net/ipv4/tcp_illinois.c
@@ -23,7 +23,9 @@
 #define ALPHA_MIN	((3*ALPHA_SCALE)/10)	/* ~0.3 */
 #define ALPHA_MAX	(10*ALPHA_SCALE)	/* 10.0 */
 #define ALPHA_BASE	ALPHA_SCALE		/* 1.0 */
+#ifndef U32_MAX
 #define U32_MAX		((u32)~0U)
+#endif /* !U32_MAX */
 #define RTT_MAX		(U32_MAX / ALPHA_MAX)	/* 3.3 secs */
 
 #define BETA_SHIFT	6