diff --git a/.github/workflows/container_dev.yml b/.github/workflows/container_dev.yml
index 999c71727..4692238a2 100644
--- a/.github/workflows/container_dev.yml
+++ b/.github/workflows/container_dev.yml
@@ -41,6 +41,8 @@ jobs:
         run: |
           sudo apt-get install -y gcc-aarch64-linux-gnu
           echo "CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_LINKER=aarch64-linux-gnu-gcc" >> "$GITHUB_ENV"
+          # Disable glibc fortify source — its __memcpy_chk etc. symbols don't exist in musl
+          echo "CFLAGS_aarch64_unknown_linux_musl=-U_FORTIFY_SOURCE" >> "$GITHUB_ENV"
 
       - name: Cache cargo registry and target
         uses: actions/cache@v5
diff --git a/.github/workflows/container_latest.yml b/.github/workflows/container_latest.yml
index dc393db65..ab1179be7 100644
--- a/.github/workflows/container_latest.yml
+++ b/.github/workflows/container_latest.yml
@@ -92,6 +92,8 @@ jobs:
         run: |
           sudo apt-get install -y gcc-aarch64-linux-gnu
           echo "CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_LINKER=aarch64-linux-gnu-gcc" >> "$GITHUB_ENV"
+          # Disable glibc fortify source — its __memcpy_chk etc. symbols don't exist in musl
+          echo "CFLAGS_aarch64_unknown_linux_musl=-U_FORTIFY_SOURCE" >> "$GITHUB_ENV"
 
       - name: Cache cargo registry and target
         uses: actions/cache@v5
diff --git a/.github/workflows/container_release_unified.yml b/.github/workflows/container_release_unified.yml
index 8218aaba9..6c7e8e215 100644
--- a/.github/workflows/container_release_unified.yml
+++ b/.github/workflows/container_release_unified.yml
@@ -74,6 +74,8 @@ jobs:
         run: |
           sudo apt-get install -y gcc-aarch64-linux-gnu
           echo "CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_LINKER=aarch64-linux-gnu-gcc" >> "$GITHUB_ENV"
+          # Disable glibc fortify source — its __memcpy_chk etc. symbols don't exist in musl
+          echo "CFLAGS_aarch64_unknown_linux_musl=-U_FORTIFY_SOURCE" >> "$GITHUB_ENV"
 
       - name: Cache cargo registry and target
         uses: actions/cache@v5