diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index 681a4d6..3bf7583 100755
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -160,6 +160,7 @@
 check_symbol_exists(getrlimit "sys/types.h;sys/time.h;sys/resource.h" HAVE_GETRLIMIT)
 check_symbol_exists(posix_spawn spawn.h HAVE_POSIX_SPAWN)
 check_symbol_exists(pread unistd.h HAVE_PREAD)
+check_symbol_exists(realpath stdlib.h HAVE_REALPATH)
 check_symbol_exists(sbrk unistd.h HAVE_SBRK)
 check_symbol_exists(srand48 stdlib.h HAVE_RAND48_SRAND48)
 if( HAVE_RAND48_SRAND48 )
diff --git a/include/llvm/Config/config.h.cmake b/include/llvm/Config/config.h.cmake
index 572fb6f..825349c 100644
--- a/include/llvm/Config/config.h.cmake
+++ b/include/llvm/Config/config.h.cmake
@@ -302,7 +302,7 @@
 #cmakedefine HAVE_READDIR ${HAVE_READDIR}
 
 /* Define to 1 if you have the `realpath' function. */
-#undef HAVE_REALPATH
+#cmakedefine HAVE_REALPATH ${HAVE_REALPATH}
 
 /* Define to 1 if you have the `rintf' function. */
 #undef HAVE_RINTF