diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 2759b06419..3c8b383205 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -341,7 +341,7 @@ jobs:
               -DCURL_USE_OPENSSL=ON -DOPENSSL_ROOT_DIR=/home/linuxbrew/.linuxbrew/opt/openssl@4
               -DCURL_USE_WOLFSSL=ON -DCURL_USE_GNUTLS=ON -DCURL_USE_MBEDTLS=ON -DCURL_USE_RUSTLS=ON
               -DCURL_USE_GSASL=ON
-              -DUSE_ECH=ON -DCURL_USE_GSSAPI=ON -DUSE_SSLS_EXPORT=ON
+              -DUSE_ECH=ON -DCURL_USE_GSSAPI=ON -DUSE_SSLS_EXPORT=ON -DCURL_DISABLE_HTTPSIG=OFF
               -DCURL_CLANG_TIDY=ON -DCLANG_TIDY=/usr/bin/clang-tidy-22
 
           - name: 'clang-tidy H3 c-ares !examples'
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index f32e01894f..61ded65495 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -345,7 +345,7 @@ jobs:
             compiler: clang
             install: brotli wolfssl zstd
             install_steps: pytest
-            generate: -DCURL_USE_WOLFSSL=ON -DCURL_DISABLE_LDAP=ON -DUSE_ECH=ON -DCURL_ENABLE_NTLM=ON
+            generate: -DCURL_USE_WOLFSSL=ON -DCURL_DISABLE_LDAP=ON -DUSE_ECH=ON -DCURL_ENABLE_NTLM=ON -DCURL_DISABLE_HTTPSIG=OFF
 
           - name: 'mbedTLS !ldap brotli zstd MultiSSL AppleIDN'
             compiler: llvm@18
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index bcee2e7330..da7dde328b 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -313,7 +313,7 @@ jobs:
           #   install: 'mingw-w64-ucrt-x86_64-libssh2' }
           - { name: 'schannel dev debug', type: 'Debug', cppflags: '-DCURL_SCHANNEL_DEV_DEBUG', image: 'windows-2025',
               build: 'cmake'    , sys: 'mingw64'   , env: 'x86_64'       , tflags: 'skiprun',
-              config: '-DENABLE_DEBUG=ON  -DBUILD_SHARED_LIBS=ON  -DCURL_USE_SCHANNEL=ON -DCURL_USE_WOLFSSL=ON -DENABLE_UNICODE=ON -DCMAKE_VERBOSE_MAKEFILE=ON',
+              config: '-DENABLE_DEBUG=ON  -DBUILD_SHARED_LIBS=ON  -DCURL_USE_SCHANNEL=ON -DCURL_USE_WOLFSSL=ON -DENABLE_UNICODE=ON -DCMAKE_VERBOSE_MAKEFILE=ON -DCURL_DISABLE_HTTPSIG=OFF',
               install: 'mingw-w64-x86_64-libssh2 mingw-w64-x86_64-wolfssl' }
           - { name: 'MultiSSL R', type: 'Release',
               build: 'cmake'    , sys: 'mingw32'   , env: 'i686'         , tflags: 'skiprun',
@@ -686,6 +686,7 @@ jobs:
               -DCURL_DROP_UNUSED=ON \
               -DCURL_WERROR=ON \
               -DUSE_LIBIDN2=OFF \
+              -DCURL_DISABLE_HTTPSIG=OFF \
               ${MATRIX_CONFIG}
           done
           if [ -d bld_chkprefill ] && ! diff -u bld/lib/curl_config.h bld_chkprefill/lib/curl_config.h; then
diff --git a/appveyor.sh b/appveyor.sh
index e9900191c5..0a40dd2812 100644
--- a/appveyor.sh
+++ b/appveyor.sh
@@ -79,6 +79,7 @@ if [ -n "${CMAKE_GENERATOR:-}" ]; then
       -DCURL_STATIC_CRT=ON \
       -DCURL_DROP_UNUSED=ON \
       -DCURL_USE_SCHANNEL=ON -DCURL_USE_LIBPSL=OFF \
+      -DCURL_DISABLE_HTTPSIG=OFF \
       ${CMAKE_GENERATE:-} \
       ${options} \
       || { cat _bld/CMakeFiles/CMake* 2>/dev/null; false; }