diff --git a/kotlin-native/tools/toolchain_builder/toolchains/arm-unknown-linux-gnueabihf/gcc-8.3.0-glibc-2.12.1-kernel-4.9.config b/kotlin-native/tools/toolchain_builder/toolchains/arm-unknown-linux-gnueabihf/gcc-8.3.0-glibc-2.12.1-kernel-4.9.config
index a83293bb544..52098c45ac7 100644
--- a/kotlin-native/tools/toolchain_builder/toolchains/arm-unknown-linux-gnueabihf/gcc-8.3.0-glibc-2.12.1-kernel-4.9.config
+++ b/kotlin-native/tools/toolchain_builder/toolchains/arm-unknown-linux-gnueabihf/gcc-8.3.0-glibc-2.12.1-kernel-4.9.config
@@ -639,7 +639,7 @@ CT_ISL_V_0_20=y
 # CT_ISL_V_0_15 is not set
 # CT_ISL_NO_VERSIONS is not set
 CT_ISL_VERSION="0.20"
-CT_ISL_MIRRORS="http://isl.gforge.inria.fr"
+CT_ISL_MIRRORS="https://libisl.sourceforge.io"
 CT_ISL_ARCHIVE_FILENAME="@{pkg_name}-@{version}"
 CT_ISL_ARCHIVE_DIRNAME="@{pkg_name}-@{version}"
 CT_ISL_ARCHIVE_FORMATS=".tar.xz .tar.bz2 .tar.gz"