diff --git a/icu4c/source/aclocal.m4 b/icu4c/source/aclocal.m4
index 8c1db773fc1..735b8ebefdb 100644
--- a/icu4c/source/aclocal.m4
+++ b/icu4c/source/aclocal.m4
@@ -251,7 +251,7 @@ AC_DEFUN(AC_CHECK_STRICT_COMPILE,
     then
         if test "$GCC" = yes
         then
-            CFLAGS="$CFLAGS -Wall -ansi -pedantic -Wshadow -Wpointer-arith -Wmissing-prototypes -Wwrite-strings -Winline -Wno-long-long"
+            CFLAGS="$CFLAGS -Wall -ansi -pedantic -Wshadow -Wpointer-arith -Wmissing-prototypes -Wwrite-strings -Winline -Wno-long-long -fno-strict-aliasing"
             case "${host}" in
             *-*-solaris*)
                 CFLAGS="$CFLAGS -D__STDC__=0";;
diff --git a/icu4c/source/configure b/icu4c/source/configure
index de0d291b238..db0ab45635d 100755
--- a/icu4c/source/configure
+++ b/icu4c/source/configure
@@ -1357,7 +1357,7 @@ fi
     then
         if test "$GCC" = yes
         then
-            CFLAGS="$CFLAGS -Wall -ansi -pedantic -Wshadow -Wpointer-arith -Wmissing-prototypes -Wwrite-strings -Winline -Wno-long-long"
+            CFLAGS="$CFLAGS -Wall -ansi -pedantic -Wshadow -Wpointer-arith -Wmissing-prototypes -Wwrite-strings -Winline -Wno-long-long -fno-strict-aliasing"
             case "${host}" in
             *-*-solaris*)
                 CFLAGS="$CFLAGS -D__STDC__=0";;