diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bde4ab27..e3316c55 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -55,7 +55,10 @@ jobs:
         override: true
 
     - name: Build documentation
-      run: cd docs && make -j$(nproc)
+      run: |
+        # https://github.com/rust-lang/cargo/issues/9919
+        export CARGO_HTTP_MULTIPLEXING=false
+        cd docs && make -j$(nproc)
 
   examples:
     name: Examples
@@ -74,8 +77,10 @@ jobs:
         override: true
 
     - name: Doctest
-      # https://github.com/rust-lang/cargo/issues/9919
-      run: cd doctest && CARGO_HTTP_MULTIPLEXING=false cargo check
+      run: |
+        # https://github.com/rust-lang/cargo/issues/9919
+        export CARGO_HTTP_MULTIPLEXING=false
+        cd doctest && cargo check
 
   rustfmt:
     name: Rustfmt
diff --git a/.github/workflows/publish-docs.yml b/.github/workflows/publish-docs.yml
index 6da913d6..8ff61674 100644
--- a/.github/workflows/publish-docs.yml
+++ b/.github/workflows/publish-docs.yml
@@ -33,7 +33,10 @@ jobs:
         override: true
 
     - name: Build documentation
-      run: cd docs && make -j$(nproc)
+      run: |
+        # https://github.com/rust-lang/cargo/issues/9919
+        export CARGO_HTTP_MULTIPLEXING=false
+        cd docs && make -j$(nproc)
 
     - name: Deploy
       uses: peaceiris/actions-gh-pages@v3