diff --git a/config_host/config_global.h.in b/config_host/config_global.h.in
index 5b42b2c5a8bd..6580fdfd0af7 100644
--- a/config_host/config_global.h.in
+++ b/config_host/config_global.h.in
@@ -13,6 +13,7 @@ Any change in this header will cause a rebuild of almost everything.
 #define CONFIG_GLOBAL_H
 
 #define HAVE_GCC_BUILTIN_ATOMIC 0
+#define HAVE_GCC_WSFINAE_INCOMPLETE 0
 #define HAVE_SYSLOG_H 0
 
 // Compiler supports C++20 <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1073r3.html>
diff --git a/configure.ac b/configure.ac
index f3761d0eeca6..f8433c6655a2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -8013,6 +8013,21 @@ AC_SUBST(HARDENING_LDFLAGS)
 AC_SUBST(HARDENING_CFLAGS)
 AC_SUBST(HARDENING_OPT_CFLAGS)
 
+if test "$GCC" = yes && test "$COM_IS_CLANG" != TRUE; then
+    AC_MSG_CHECKING([whether $CXX_BASE supports -Wsfinae-incomplete])
+    AC_LANG_PUSH([C++])
+    save_CXXFLAGS=$CFLAGS
+    CXXFLAGS="$CXXFLAGS -Werror"
+    AC_COMPILE_IFELSE([AC_LANG_SOURCE([
+            #pragma GCC diagnostic warning "-Wsfinae-incomplete"
+        ])], [
+            AC_DEFINE([HAVE_GCC_WSFINAE_INCOMPLETE])
+            AC_MSG_RESULT([yes])
+        ], [AC_MSG_RESULT([no])])
+    CXXFLAGS=$save_CXXFLAGS
+    AC_LANG_POP([C++])
+fi
+
 dnl ===================================================================
 dnl Identify the C++ library
 dnl ===================================================================
diff --git a/include/vcl/vclptr.hxx b/include/vcl/vclptr.hxx
index 228a14c27482..8333f1a1b1a4 100644
--- a/include/vcl/vclptr.hxx
+++ b/include/vcl/vclptr.hxx
@@ -22,6 +22,7 @@
 
 #include <sal/config.h>
 
+#include <config_global.h>
 #include <rtl/ref.hxx>
 
 #include <utility>
@@ -44,6 +45,24 @@ template<typename T> constexpr bool isIncompleteOrDerivedFromVclReferenceBase(
     int (*)[sizeof(T)])
 { return std::is_base_of<VclReferenceBase, T>::value; }
 
+// The above isIncompleteOrDerivedFromVclReferenceBase will cause will cause -Wsfinae-incomplete
+// warnings when e.g. OutputDevice (include/vcl/outdev.hxx) contains members of type
+// VclPtr<OutputDevice>, so OutputDevice is not yet complete when
+// sIncompleteOrDerivedFromVclReferenceBase is instantiated, but will become complete later on
+// ("warning: error: defining ‘OutputDevice’, which previously failed to be complete in a SFINAE
+// context [-Werror=sfinae-incomplete=]").  A real solution would presumably be using C++26
+// reflection and rewriting the above isIncompleteOrDerivedFromVclReferenceBase as something like
+//
+//  consteval bool isIncompleteOrDerivedFromVclReferenceBase(std::meta::info type) {
+//      return !std::meta::is_complete_type(type)
+//          || std::meta::is_base_of_type(^^VclReferenceBase, type);
+//  }
+//
+// But until then, use a HACK of (globally) ignoring that warning:
+#if defined __GNUC__ && !defined __clang__ && HAVE_GCC_WSFINAE_INCOMPLETE
+#pragma GCC diagnostic ignored "-Wsfinae-incomplete"
+#endif
+
 } // namespace vcl::detail
 
 /**