diff --git a/llvm-core/flang/flang-21.0.0.9999.ebuild b/llvm-core/flang/flang-21.0.0.9999.ebuild
index a5cd1ef77ae31..97f8cb4a73c04 100644
--- a/llvm-core/flang/flang-21.0.0.9999.ebuild
+++ b/llvm-core/flang/flang-21.0.0.9999.ebuild
@@ -20,6 +20,7 @@ DEPEND="
 "
 RDEPEND="
 	${DEPEND}
+	>=llvm-runtimes/flang-rt-${PV}:${LLVM_MAJOR}
 "
 BDEPEND="
 	test? (
@@ -27,7 +28,7 @@ BDEPEND="
 	)
 "
 
-LLVM_COMPONENTS=( flang flang-rt cmake )
+LLVM_COMPONENTS=( flang cmake )
 LLVM_TEST_COMPONENTS=( clang/test/Driver mlir/test/lib )
 llvm.org_set_globals
 
@@ -43,6 +44,8 @@ src_configure() {
 		# flang does not feature a dylib, so do not install libraries
 		# or headers
 		-DLLVM_INSTALL_TOOLCHAIN_ONLY=ON
+		# installed by llvm-runtimes/flang-rt
+		-DFLANG_INCLUDE_RUNTIME=OFF
 
 		# TODO: always enable to obtain reproducible tools
 		-DFLANG_INCLUDE_TESTS=$(usex test)
@@ -62,11 +65,3 @@ src_test() {
 	local -x LIT_PRESERVES_TMP=1
 	cmake_build check-flang
 }
-
-src_install() {
-	cmake_src_install
-
-	# move the runtime into 'lib' (sigh), until upstream resolves
-	# libdir support: https://github.com/llvm/llvm-project/issues/127538
-	mv "${ED}/usr/lib/llvm/${LLVM_MAJOR}"/{$(get_libdir),lib} || die
-}
diff --git a/llvm-core/flang/flang-21.0.0_pre20250221-r1.ebuild b/llvm-core/flang/flang-21.0.0_pre20250221-r1.ebuild
new file mode 100644
index 0000000000000..97f8cb4a73c04
--- /dev/null
+++ b/llvm-core/flang/flang-21.0.0_pre20250221-r1.ebuild
@@ -0,0 +1,67 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit cmake llvm.org
+
+DESCRIPTION="LLVM's Fortran frontend"
+HOMEPAGE="https://flang.llvm.org/"
+
+LICENSE="Apache-2.0-with-LLVM-exceptions"
+SLOT="${LLVM_MAJOR}/${LLVM_SOABI}"
+IUSE="+debug test"
+RESTRICT="!test? ( test )"
+
+DEPEND="
+	~llvm-core/clang-${PV}[debug=]
+	~llvm-core/llvm-${PV}[debug=]
+	~llvm-core/mlir-${PV}[debug=]
+"
+RDEPEND="
+	${DEPEND}
+	>=llvm-runtimes/flang-rt-${PV}:${LLVM_MAJOR}
+"
+BDEPEND="
+	test? (
+		dev-python/lit
+	)
+"
+
+LLVM_COMPONENTS=( flang cmake )
+LLVM_TEST_COMPONENTS=( clang/test/Driver mlir/test/lib )
+llvm.org_set_globals
+
+src_configure() {
+	local mycmakeargs=(
+		-DCMAKE_INSTALL_PREFIX="${EPREFIX}/usr/lib/llvm/${LLVM_MAJOR}"
+
+		-DLLVM_ROOT="${ESYSROOT}/usr/lib/llvm/${LLVM_MAJOR}"
+		-DCLANG_RESOURCE_DIR="../../../clang/${LLVM_MAJOR}"
+
+		-DBUILD_SHARED_LIBS=OFF
+		-DMLIR_LINK_MLIR_DYLIB=ON
+		# flang does not feature a dylib, so do not install libraries
+		# or headers
+		-DLLVM_INSTALL_TOOLCHAIN_ONLY=ON
+		# installed by llvm-runtimes/flang-rt
+		-DFLANG_INCLUDE_RUNTIME=OFF
+
+		# TODO: always enable to obtain reproducible tools
+		-DFLANG_INCLUDE_TESTS=$(usex test)
+	)
+	use test && mycmakeargs+=(
+		-DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
+		-DLLVM_LIT_ARGS="$(get_lit_flags)"
+	)
+
+	# LLVM_ENABLE_ASSERTIONS=NO does not guarantee this for us, #614844
+	use debug || local -x CPPFLAGS="${CPPFLAGS} -DNDEBUG"
+	cmake_src_configure
+}
+
+src_test() {
+	# respect TMPDIR!
+	local -x LIT_PRESERVES_TMP=1
+	cmake_build check-flang
+}