diff --git a/.cirrus.yml b/.cirrus.yml
index 68e5bc5a..9b4ff109 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -142,7 +142,7 @@ task:
     apt-get update
     apt-get install -y powershell
   configure_script:
-    - ./configure --with-tclsh=tclsh8.6 --prefix /tmp/modules --with-tcl=/usr/lib/tcl8.6 --enable-append-manpath --enable-append-binpath --with-bin-search-path=/usr/bin:/bin --enable-silent-shell-debug-support --enable-windows-support --with-loadedmodules=null:dot --enable-quarantine-support --with-quarantine-vars=LD_LIBRARY_PATH --with-dark-background-colors='hi=1:se=2:er=91:wa=93:mp=1;94:di=94:al=96:sy=95' --enable-foo FOO=bar
+    - ./configure --with-tclsh=tclsh8.6 --prefix /tmp/modules --with-tcl=/usr/lib/tcl8.6 --enable-append-manpath --enable-append-binpath --with-bin-search-path=/usr/bin:/bin --enable-silent-shell-debug-support --enable-windows-support --with-loadedmodules=null:dot --enable-quarantine-support --with-quarantine-vars=LD_LIBRARY_PATH --enable-new-features --with-dark-background-colors='hi=1:se=2:er=91:wa=93:mp=1;94:di=94:al=96:sy=95' --enable-foo FOO=bar
   << : *BUILD_INSTALL_TEST_TEMPLATE
   << : *ARTIFACTS_TEMPLATE
 
diff --git a/.github/workflows/linux_tests.yaml b/.github/workflows/linux_tests.yaml
index bca67ba5..f46ca558 100644
--- a/.github/workflows/linux_tests.yaml
+++ b/.github/workflows/linux_tests.yaml
@@ -196,7 +196,7 @@ jobs:
   tcl86:
     runs-on: ubuntu-20.04
     env:
-      CONFIGURE_OPTS: --with-tclsh=tclsh8.6 --prefix=/tmp/modules --libdir=/tmp/modules/lib64 --enable-multilib-support
+      CONFIGURE_OPTS: --with-tclsh=tclsh8.6 --prefix=/tmp/modules --libdir=/tmp/modules/lib64 --enable-multilib-support --enable-new-features
       COVERAGE: y
       COVERAGE_OLDTCL: y
       COVERAGE_MULTILIB: y