diff --git a/.github/workflows/build_rocky.yml b/.github/workflows/build_rocky.yml
index 1aa534b5a1..0debde5ed6 100644
--- a/.github/workflows/build_rocky.yml
+++ b/.github/workflows/build_rocky.yml
@@ -81,7 +81,7 @@ jobs:
         shell: bash
         run: |
           set -o pipefail
-          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release BUILD_BONSAIVIEWER=ON \
+          CXXFLAGS="-O3" CFLAGS="-O3" ADD_COMMIT_SHA=1 BUILD_CFG=Release BUILD_BONSAIVIEWER=ON \
             uv run --with aqtinstall ./nix/build-all.py \
             -v --diskcleanup --shared 2>&1 \
             | tee build.log
diff --git a/.github/workflows/build_rocky_arm.yml b/.github/workflows/build_rocky_arm.yml
index 052117ed0c..6c76766fe5 100644
--- a/.github/workflows/build_rocky_arm.yml
+++ b/.github/workflows/build_rocky_arm.yml
@@ -92,7 +92,7 @@ jobs:
         shell: bash
         run: |
           set -o pipefail
-          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release BUILD_BONSAIVIEWER=ON \
+          CXXFLAGS="-O3" CFLAGS="-O3" ADD_COMMIT_SHA=1 BUILD_CFG=Release BUILD_BONSAIVIEWER=ON \
             uv run --with aqtinstall ./nix/build-all.py \
             -v --diskcleanup --shared 2>&1 \
             | tee build.log