diff --git a/Ports/AvailablePorts.md b/Ports/AvailablePorts.md
index 0e89d8cad0..f515424f46 100644
--- a/Ports/AvailablePorts.md
+++ b/Ports/AvailablePorts.md
@@ -80,6 +80,7 @@ Please make sure to keep this list up to date when adding and updating ports. :^
 | [`imagemagick`](imagemagick/)          | ImageMagick                                                     | 7.1.0-29                 | https://imagemagick.org                                                        |
 | [`imgcat`](imgcat/)                    | imgcat                                                          | 2.5.0                    | https://github.com/eddieantonio/imgcat                                         |
 | [`indent`](indent/)                    | GNU indent                                                      | 2.2.11                   | https://www.gnu.org/software/indent/                                           |
+| [`isl`](isl/)                          | Integer Set Library                                             | 0.24                     | https://libisl.sourceforge.io/                                                 |
 | [`ja2`](ja2/)                          | Jagged Alliance 2 Stracciatella                                 | 0.15.x                   | https://github.com/safarp/ja2-stracciatella/tree/0.15.x                        |
 | [`jot`](jot/)                          | jot (OpenBSD)                                                   | 6.6                      | https://github.com/ibara/libpuffy                                              |
 | [`jq`](jq/)                            | jq                                                              | 1.6                      | https://stedolan.github.io/jq/                                                 |
diff --git a/Ports/isl/package.sh b/Ports/isl/package.sh
new file mode 100755
index 0000000000..c010193a41
--- /dev/null
+++ b/Ports/isl/package.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env -S bash ../.port_include.sh
+port=isl
+version=0.24
+useconfigure=true
+use_fresh_config_sub=true
+files="https://libisl.sourceforge.io/isl-${version}.tar.xz isl-${version}.tar.xz 043105cc544f416b48736fff8caf077fb0663a717d06b1113f16e391ac99ebad"
+auth_type=sha256
+depends=("gmp")
+
+if [ "$SERENITY_TOOLCHAIN" = "Clang" ]; then
+    # This test fails with Clang because it doesn't let you take the address of compiler intrinsics.
+    export ac_cv_have_decl___builtin_ffs=yes
+fi