--- a/perl-5.34.0.ebuild	2021-07-21 06:09:38.000000000 +0300
+++ b/perl-5.34.0.ebuild	2021-07-25 16:46:15.344009592 +0300
@@ -56,7 +56,7 @@
 KEYWORDS="~alpha amd64 arm arm64 hppa ~ia64 ~m68k ~mips ppc ppc64 ~riscv ~s390 sparc x86 ~x64-cygwin ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~sparc-solaris ~sparc64-solaris ~x64-solaris ~x86-solaris"
 fi
 
-IUSE="berkdb debug doc gdbm ithreads minimal"
+IUSE="berkdb debug doc gdbm ithreads minimal +system-zlib"
 
 RDEPEND="
 	berkdb? ( sys-libs/db:= )
@@ -545,9 +545,11 @@
 	export BZIP2_INCLUDE=${EROOT}/usr/include
 	export BZIP2_LIB=${EROOT}/usr/$(get_libdir)
 
-	export BUILD_ZLIB=False
-	export ZLIB_INCLUDE=${EROOT}/usr/include
-	export ZLIB_LIB=${EROOT}/usr/$(get_libdir)
+	export BUILD_ZLIB=$(usex system-zlib False True)
+	if use system-zlib ; then
+		export ZLIB_INCLUDE=${EROOT}/usr/include
+		export ZLIB_LIB=${EROOT}/usr/$(get_libdir)
+	fi
 
 	# allow either gdbm to provide ndbm (in <gdbm/ndbm.h>) or db1
 	myndbm='U'