diff --git a/.github/actions/setup-z3/action.yml b/.github/actions/setup-z3/action.yml
index 1387ac87..8bd92fd5 100644
--- a/.github/actions/setup-z3/action.yml
+++ b/.github/actions/setup-z3/action.yml
@@ -4,24 +4,20 @@ inputs:
   z3-version:
     description: The version of Z3 to install.
     required: false
-    default: 4.13.0
+    default: 4.15.4
   z3-variant:
-    description: The variant of Z3 to install.
+    description: The variant of Z3 to install (includes arch, e.g. x64-glibc-2.39, arm64-glibc-2.34).
     required: false
-    default: glibc-2.35
+    default: x64-glibc-2.39
   z3-sha256sum:
     description: Expected sha256sum of downloaded binary archive.
     required: false
     default: |
-      884e3a411fa11b125522fc35eba3391b772517c047f8064fb4b656d92a73b38c  z3-4.13.0-x64-glibc-2.35.zip
-      bc31ad12446d7db1bd9d0ac82dec9d7b5129b8b8dd6e44b571a83ac6010d2f9b  z3-4.13.0-x64-glibc-2.31.zip
-      50fae93d74689bc3460bec939273cf602a4c6f60a047f2a9cf48f609dc444d48  z3-4.13.0-arm64-glibc-2.35.zip
+      a41b690e89c343931471506cdc6d957b6044a200fd2d240cc017432afdff7d3e  z3-4.15.4-x64-glibc-2.39.zip
+      9e832578e28d9ed51a79b97948728a874854a3c38ee49e7aae05e7d6e0e93508  z3-4.15.4-arm64-glibc-2.34.zip
 runs:
   using: composite
   steps:
-    - id: arch
-      shell: bash
-      run: echo "z3-arch=$RUNNER_ARCH" | tr '[:upper:]' '[:lower:]' >> $GITHUB_OUTPUT
     - shell: bash
       run: |
         wget -q "$RELEASE_URL/$RELEASE_NAME.zip"
@@ -32,5 +28,5 @@ runs:
         echo ~/.setup-z3/bin >> $GITHUB_PATH
       env:
         RELEASE_URL: https://github.com/Z3Prover/z3/releases/download/z3-${{ inputs.z3-version }}
-        RELEASE_NAME: z3-${{ inputs.z3-version }}-${{ steps.arch.outputs.z3-arch }}-${{ inputs.z3-variant }}
+        RELEASE_NAME: z3-${{ inputs.z3-version }}-${{ inputs.z3-variant }}
         INPUT_Z3_SHA256SUM: ${{ inputs.z3-sha256sum }}