diff --git a/icu4c/source/common/unicode/utypes.h b/icu4c/source/common/unicode/utypes.h
index a99898b662..12db1e9e38 100644
--- a/icu4c/source/common/unicode/utypes.h
+++ b/icu4c/source/common/unicode/utypes.h
@@ -185,27 +185,6 @@ typedef uint8_t UVersionInfo[U_MAX_VERSION_LENGTH];
 #endif
 #endif
 
-/**
- * \def U_MAX_PTR
- * Maximum value of a (void*) - use to indicate the limit of an 'infinite' buffer.
- * In fact, buffer sizes must not exceed 2GB so that the difference between
- * the buffer limit and the buffer start can be expressed in an int32_t.
- *
- * The definition of U_MAX_PTR must fulfill the following conditions:
- * - return the largest possible pointer greater than base
- * - return a valid pointer according to the machine architecture (AS/400, 64-bit, etc.)
- * - avoid wrapping around at high addresses
- * - make sure that the returned pointer is not farther from base than 0x7fffffff
- *
- * For some architectures (like AS/400), a custom macro must be defined in platform.h.in or similar.
- *
- * @param base The beginning of a buffer to find the maximum offset from
- * @internal
- */
-#ifndef U_MAX_PTR
-#   define U_MAX_PTR(base) ((void *)(((char *)(base)+0x7fffffff)>(char *)(base) ? ((char *)(base)+0x7fffffff) : (char *)-1))
-#endif
-
 /*===========================================================================*/
 /* Calendar/TimeZone data types                                              */
 /*===========================================================================*/