--- a/gfx/wr/.taskcluster.yml
+++ b/gfx/wr/.taskcluster.yml
@@ -59,22 +59,17 @@ tasks:
           provisionerId: proj-webrender
           workerType: ci-linux
           deadline: {$fromNow: '1 day'}
           payload:
             maxRunTime: 7200
             image: 'staktrace/webrender-test:debian-v3'
             env:
               RUST_BACKTRACE: 'full'
-              #############################################################
-              ### Temporarily disable until https://bugzil.la/1564873 lands
-              ### in order to unblock https://bugzil.la/1575648 (which is
-              ### time-critical)
-              # RUSTFLAGS: '--deny warnings'
-              #############################################################
+              RUSTFLAGS: '--deny warnings'
             command:
               - /bin/bash
               - '--login'
               - '-c'
               - >-
                 curl https://sh.rustup.rs -sSf | sh -s -- -y &&
                 source $HOME/.cargo/env &&
                 git clone ${repo_url} webrender && cd webrender &&
@@ -91,22 +86,17 @@ tasks:
           provisionerId: proj-webrender
           workerType: ci-linux
           deadline: {$fromNow: '1 day'}
           payload:
             maxRunTime: 7200
             image: 'staktrace/webrender-test:debian-v3'
             env:
               RUST_BACKTRACE: 'full'
-              #############################################################
-              ### Temporarily disable until https://bugzil.la/1564873 lands
-              ### in order to unblock https://bugzil.la/1575648 (which is
-              ### time-critical)
-              # RUSTFLAGS: '--deny warnings'
-              #############################################################
+              RUSTFLAGS: '--deny warnings'
             command:
               - /bin/bash
               - '--login'
               - '-c'
               - >-
                 curl https://sh.rustup.rs -sSf | sh -s -- -y &&
                 source $HOME/.cargo/env &&
                 git clone ${repo_url} webrender && cd webrender &&
@@ -140,22 +130,17 @@ tasks:
                 - '-vec'
                 - |
                   git clone ${repo_url} webrender
                   cd webrender
                   git checkout ${sha}
                   source $HOME/servotidy-venv/bin/activate
                   servo-tidy
                   export RUST_BACKTRACE=full
-                  #############################################################
-                  ### Temporarily disable until https://bugzil.la/1564873 lands
-                  ### in order to unblock https://bugzil.la/1575648 (which is
-                  ### time-critical)
-                  # export RUSTFLAGS='--deny warnings'
-                  #############################################################
+                  export RUSTFLAGS='--deny warnings'
                   export PKG_CONFIG_PATH="/usr/local/opt/zlib/lib/pkgconfig:$PKG_CONFIG_PATH"
                   echo 'exec make -j1 "$@"' > $HOME/make # See #2638
                   chmod +x $HOME/make
                   export MAKE="$HOME/make"
                   ci-scripts/macos-release-tests.sh
           routes:
             - "index.project.webrender.ci.${login}.${branch}.osx-release"
         - metadata:
@@ -174,21 +159,16 @@ tasks:
                 - '-vec'
                 - |
                   git clone ${repo_url} webrender
                   cd webrender
                   git checkout ${sha}
                   source $HOME/servotidy-venv/bin/activate
                   servo-tidy
                   export RUST_BACKTRACE=full
-                  #############################################################
-                  ### Temporarily disable until https://bugzil.la/1564873 lands
-                  ### in order to unblock https://bugzil.la/1575648 (which is
-                  ### time-critical)
-                  # export RUSTFLAGS='--deny warnings'
-                  #############################################################
+                  export RUSTFLAGS='--deny warnings'
                   export PKG_CONFIG_PATH="/usr/local/opt/zlib/lib/pkgconfig:$PKG_CONFIG_PATH"
                   echo 'exec make -j1 "$@"' > $HOME/make # See #2638
                   chmod +x $HOME/make
                   export MAKE="$HOME/make"
                   ci-scripts/macos-debug-tests.sh
           routes:
             - "index.project.webrender.ci.${login}.${branch}.osx-debug"