diff --git a/.github/workflows/linux-upstream-zlib-ng.yml b/.github/workflows/linux-upstream-zlib-ng.yml
index 1f1e799..318e758 100644
--- a/.github/workflows/linux-upstream-zlib-ng.yml
+++ b/.github/workflows/linux-upstream-zlib-ng.yml
@@ -15,7 +15,7 @@ jobs:
     strategy:
       matrix:
         perl:
-          - '5.38'
+          - latest
         zlib-version:
           - 'develop'
           - '2.1.6'
@@ -84,7 +84,7 @@ jobs:
       with:
         # NOTE: path doesn't expand variables!
         path: upstream-zlib-install
-        key: ${{ runner.os }}-zlib-ng-${{ matrix.zlib-version }}-${{ matrix.zlib-native }}
+        key: ${{ runner.os }}-${{ runner.arch }}-zlib-ng-${{ matrix.zlib-version }}-${{ matrix.zlib-native }}
 
     - name: Wipe develop cached files, if found
       if: env.STEP_ENABLED && matrix.zlib-version == 'develop' && steps.cache-zlib.outputs.cache-hit
diff --git a/.github/workflows/linux-upstream-zlib.yml b/.github/workflows/linux-upstream-zlib.yml
index ccc98d4..3cf5e3c 100644
--- a/.github/workflows/linux-upstream-zlib.yml
+++ b/.github/workflows/linux-upstream-zlib.yml
@@ -18,7 +18,7 @@ jobs:
     strategy:
       matrix:
         perl:
-          - '5.38'
+          - latest
         zlib-version:
           - v1.3.1
           - v1.3
@@ -82,7 +82,7 @@ jobs:
       with:
         # NOTE: path doesn't expand variables!
         path: upstream-zlib-install
-        key: ${{ runner.os }}-zlib-${{ matrix.zlib-version }}
+        key: ${{ runner.os }}-${{ runner.arch }}-zlib-${{ matrix.zlib-version }}
 
     - name: Wipe develop cached files, if found
       if: env.STEP_ENABLED && matrix.zlib-version == 'develop' && steps.cache-zlib.outputs.cache-hit
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index f5f0292..b915871 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -13,6 +13,7 @@ jobs:
     strategy:
       matrix:
         perl:
+          - '5.40'
           - '5.38'
           - '5.36'
           - '5.34'
@@ -36,24 +37,74 @@ jobs:
           - 1
 
         cc-opts:
-            - ""
-            - -Wc++-compat
+            - -Werror
+            - -Werror -Wc++-compat
 
     name: Perl ${{ matrix.perl }} BUILD_ZLIB:${{matrix.build-zlib}} ${{matrix.cc-opts}}
     steps:
     - uses: actions/checkout@v4
+
+    - name: Setup perl
+      uses: shogo82148/actions-setup-perl@v1
+      with:
+        perl-version: ${{ matrix.perl }}
+
+    - name: Perl version
+      run: perl -V
+
+    - name: Install dependencies
+      run: cpanm --quiet --installdeps --notest .
+
+    - name: Build
+      run: |
+        flags=$( perl -MConfig -e 'print $Config::Config{ccflags}' )
+        perl Makefile.PL CCFLAGS="$flags ${{matrix.cc-opts}}" && make
+      env:
+        BUILD_ZLIB: ${{matrix.build-zlib}}
+
+    - name: Test
+      run: make test
+
+
+
+  werror:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        perl:
+          - latest
+
+        compiler:
+          - gcc
+          - g++
+
+        build-zlib:
+          - 0
+          - 1
+
+    name: Perl ${{ matrix.perl }} BUILD_ZLIB:${{matrix.build-zlib}} ${{matrix.compiler}}
+    steps:
+    - uses: actions/checkout@v4
+
     - name: Setup perl
       uses: shogo82148/actions-setup-perl@v1
       with:
         perl-version: ${{ matrix.perl }}
+
     - name: Perl version
       run: perl -V
+
     - name: Install dependencies
       run: cpanm --quiet --installdeps --notest .
+
     - name: Build
-      run: perl Makefile.PL && make
+      run: |
+        flags=$( perl -MConfig -e 'print $Config::Config{ccflags}' )
+        perl Makefile.PL CCFLAGS="$flags -Werror" CC=${{matrix.compiler}} && make
       env:
         BUILD_ZLIB: ${{matrix.build-zlib}}
-        PERL_MM_OPT: CCFLAGS=-Werror ${{matrix.cc-opts}}
+
     - name: Test
       run: make test
diff --git a/.github/workflows/macos-upstream-zlib-ng.yml b/.github/workflows/macos-upstream-zlib-ng.yml
index 8a929ad..4746b16 100644
--- a/.github/workflows/macos-upstream-zlib-ng.yml
+++ b/.github/workflows/macos-upstream-zlib-ng.yml
@@ -15,13 +15,13 @@ jobs:
     strategy:
       matrix:
         perl:
-          - '5.38'
+          - latest
         zlib-version:
           - 'develop'
           - '2.1.6'
           - '2.1.5'
           - '2.1.4'
-          - '2.1.3'
+        # - '2.1.3'
           - '2.1.2'
           - '2.0.7'
           - '2.0.6'
@@ -84,7 +84,7 @@ jobs:
       with:
         # NOTE: path doesn't expand variables!
         path: upstream-zlib-install
-        key: ${{ runner.os }}-zlib-ng-${{ matrix.zlib-version }}-${{ matrix.zlib-native }}
+        key: ${{ runner.os }}-${{ runner.arch }}-zlib-ng-${{ matrix.zlib-version }}-${{ matrix.zlib-native }}
 
     - name: Wipe develop cached files, if found
       if: env.STEP_ENABLED && matrix.zlib-version == 'develop' && steps.cache-zlib.outputs.cache-hit
diff --git a/.github/workflows/macos-upstream-zlib.yml b/.github/workflows/macos-upstream-zlib.yml
index 5022c29..d9c7438 100644
--- a/.github/workflows/macos-upstream-zlib.yml
+++ b/.github/workflows/macos-upstream-zlib.yml
@@ -18,7 +18,7 @@ jobs:
     strategy:
       matrix:
         perl:
-          - '5.38'
+          - latest
         zlib-version:
           - v1.3.1
           - v1.3
@@ -82,7 +82,7 @@ jobs:
       with:
         # NOTE: path doesn't expand variables!
         path: upstream-zlib-install
-        key: ${{ runner.os }}-zlib-${{ matrix.zlib-version }}
+        key: ${{ runner.os }}-${{runner.arch}}-zlib-${{ matrix.zlib-version }}
 
     - name: Wipe develop cached files, if found
       if: env.STEP_ENABLED && matrix.zlib-version == 'develop' && steps.cache-zlib.outputs.cache-hit
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index dadd570..533fdbe 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -13,6 +13,7 @@ jobs:
     strategy:
       matrix:
         perl:
+          - '5.40'
           - '5.38'
           - '5.36'
           - '5.34'
@@ -37,17 +38,69 @@ jobs:
     name: Perl ${{ matrix.perl }} BUILD_ZLIB:${{matrix.build-zlib}}
     steps:
     - uses: actions/checkout@v4
+
     - name: Setup perl
       uses: shogo82148/actions-setup-perl@v1
       with:
         perl-version: ${{ matrix.perl }}
+
     - name: Perl version
       run: perl -V
+
     - name: Install dependencies
       run: cpanm --quiet --installdeps --notest .
+
     - name: Build
       run: perl Makefile.PL && make
       env:
         BUILD_ZLIB: ${{matrix.build-zlib}}
+
+    - name: Test
+      run: make test
+
+
+
+  werror:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        perl:
+          - latest
+
+        compiler:
+          - name: clang
+            werror: -Werror
+
+          - name: clang++
+            werror: -Werror -Wno-error=deprecated
+
+        build-zlib:
+          - 0
+          - 1
+
+    name: Perl ${{ matrix.perl }} BUILD_ZLIB:${{matrix.build-zlib}} ${{matrix.compiler.name}}
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Setup perl
+      uses: shogo82148/actions-setup-perl@v1
+      with:
+        perl-version: ${{ matrix.perl }}
+
+    - name: Perl version
+      run: perl -V
+
+    - name: Install dependencies
+      run: cpanm --quiet --installdeps --notest .
+
+    - name: Build
+      run: |
+        flags=$( perl -MConfig -e 'print $Config::Config{ccflags}' )
+        perl Makefile.PL CCFLAGS="$flags ${{matrix.compiler.werror}} " CC=${{matrix.compiler.name}} && make
+      env:
+        BUILD_ZLIB: ${{matrix.build-zlib}}
+
     - name: Test
       run: make test
diff --git a/.github/workflows/windows-upstream-zlib-ng.yml b/.github/workflows/windows-upstream-zlib-ng.yml
index 06c6a28..3413c02 100644
--- a/.github/workflows/windows-upstream-zlib-ng.yml
+++ b/.github/workflows/windows-upstream-zlib-ng.yml
@@ -25,7 +25,7 @@ jobs:
     strategy:
       matrix:
         perl:
-          - '5.38'
+          - latest
         zlib-version:
           - 'develop'
           - '2.1.6'
@@ -89,7 +89,7 @@ jobs:
         with:
           # NOTE: path doesn't expand variables!
           path: upstream-zlib-install
-          key: ${{ runner.os }}-zlib-ng-${{ matrix.zlib-version }}-${{ matrix.zlib-native }}
+          key: ${{ runner.os }}-${{ runner.arch }}-zlib-ng-${{ matrix.zlib-version }}-${{ matrix.zlib-native }}
 
       - name: Wipe develop cached files, if found
         if: env.STEP_ENABLED && matrix.zlib-version == 'develop' && steps.cache-zlib.outputs.cache-hit
diff --git a/.github/workflows/windows-upstream-zlib.yml b/.github/workflows/windows-upstream-zlib.yml
index 6693ded..8cf6666 100644
--- a/.github/workflows/windows-upstream-zlib.yml
+++ b/.github/workflows/windows-upstream-zlib.yml
@@ -20,7 +20,7 @@ jobs:
     strategy:
       matrix:
         perl:
-          - '5.38'
+          - latest
         zlib-version:
           - v1.2.13
           - v1.2.12
@@ -58,7 +58,7 @@ jobs:
       with:
         # NOTE: path doesn't expand variables!
         path: upstream-zlib-install
-        key: ${{ runner.os }}-zlib-${{ matrix.zlib-version }}
+        key: ${{ runner.os }}-${{ runner.arch }}-zlib-${{ matrix.zlib-version }}
 
     # - name: Cancel if Scheduled Job and not running the 'develop' branch
     #   if: github.event_name == 'schedule' &&  matrix.zlib-version != 'develop'
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index b186ae1..f084344 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -13,6 +13,7 @@ jobs:
     strategy:
       matrix:
         perl:
+          - '5.40'
           - '5.38'
           - '5.36'
           - '5.34'
@@ -40,18 +41,65 @@ jobs:
     name: Perl ${{ matrix.perl }}  distribution:${{ matrix.distribution }} BUILD_ZLIB:${{matrix.build-zlib}}
     steps:
     - uses: actions/checkout@v4
+
     - name: Setup perl
       uses: shogo82148/actions-setup-perl@v1
       with:
         perl-version: ${{ matrix.perl }}
         distribution: ${{ matrix.distribution }}
+
     - name: Perl version
       run: perl -V
+
     - name: Install dependencies
       run: cpanm --quiet --installdeps --notest .
+
     - name: Build
       run: perl Makefile.PL && make
       env:
         BUILD_ZLIB: ${{matrix.build-zlib}}
+
+    - name: Test
+      run: make test
+
+  werror:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        perl:
+          - latest
+
+        compiler:
+          - gcc
+          - g++
+
+        build-zlib:
+          - 0
+          - 1
+
+    name: Perl ${{ matrix.perl }} BUILD_ZLIB:${{matrix.build-zlib}} ${{matrix.compiler}}
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Setup perl
+      uses: shogo82148/actions-setup-perl@v1
+      with:
+        perl-version: ${{ matrix.perl }}
+
+    - name: Perl version
+      run: perl -V
+
+    - name: Install dependencies
+      run: cpanm --quiet --installdeps --notest .
+
+    - name: Build
+      run: |
+        flags=$( perl -MConfig -e 'print $Config::Config{ccflags}' )
+        perl Makefile.PL CCFLAGS="$flags -Werror" CC=${{matrix.compiler}} && make
+      env:
+        BUILD_ZLIB: ${{matrix.build-zlib}}
+
     - name: Test
       run: make test