diff --git a/icu4c/source/tools/tzcode/Makefile.in b/icu4c/source/tools/tzcode/Makefile.in
index d1008426136..ac517714788 100644
--- a/icu4c/source/tools/tzcode/Makefile.in
+++ b/icu4c/source/tools/tzcode/Makefile.in
@@ -27,7 +27,8 @@ TDATA =	$(PRIMARY_DATA) $(SUPPLEMENTAL_DATA)
 
 TZDIR=zoneinfo
 
-CFLAGS+=-D_POSIX_C_SOURCE
+# https://man7.org/linux/man-pages/man2/symlink.2.html
+CFLAGS+=-D_POSIX_C_SOURCE=200112L
 CPPFLAGS+= -DTZDIR=\"$(TZDIR)\" 
 
 # more data
diff --git a/icu4c/source/tools/tzcode/zic.c b/icu4c/source/tools/tzcode/zic.c
index ed3e79239df..54576780d5f 100644
--- a/icu4c/source/tools/tzcode/zic.c
+++ b/icu4c/source/tools/tzcode/zic.c
@@ -3,9 +3,6 @@
 ** 2006-07-17 by Arthur David Olson.
 */
 
-/* https://man7.org/linux/man-pages/man2/symlink.2.html */
-#define _POSIX_C_SOURCE 200112L
-
 /* Enable extensions and modifications for ICU. */
 #define ICU