diff --git a/.github/workflows/icu4c.yml b/.github/workflows/icu4c.yml
index 78e890486983..96841f0ed150 100644
--- a/.github/workflows/icu4c.yml
+++ b/.github/workflows/icu4c.yml
@@ -329,7 +329,7 @@ jobs:
           run: |
             wget https://apt.llvm.org/llvm.sh
             chmod u+x llvm.sh
-            sudo ./llvm.sh 18
+            sudo ./llvm.sh 18 all
             clang-18 --version
         - name: Clang-18 build and Test
           env: