--- a/configure.ac
+++ b/configure.ac
@@ -381,13 +381,7 @@
 dnl ======================================================================
 dnl check another libraries
 dnl ======================================================================
-AX_PTHREAD([],
-	[case $host_os in
-	 cygwin* | mingw*)
-	 ;;
-	 *)
-	 AC_MSG_ERROR([*** pthread library are required])
-	 esac])
+AX_PTHREAD([],AC_MSG_ERROR([*** pthread library are required]))
 
 GOBJECT_INTROSPECTION_CHECK([1.30.0])
 if test "x$enable_introspection" != "xyes"; then
--- a/liblangtag/Makefile.am
+++ b/liblangtag/Makefile.am
@@ -213,6 +213,7 @@
 	$(NULL)
 liblangtag_la_LDFLAGS =						\
 	$(LDFLAGS)						\
+	-no-undefined						\
 	-version-info $(LT_CURRENT):$(LT_REVISION):$(LT_AGE)	\
 	$(NULL)
 
--- a/liblangtag/lt-atomic.h
+++ b/liblangtag/lt-atomic.h
@@ -37,6 +37,7 @@
 
 /*< public >*/
 #ifdef _WIN32
+#include <windows.h>
 LT_INLINE_FUNC int
 lt_atomic_int_get(volatile int *v)
 {
--- a/liblangtag-gobject/Makefile.am
+++ b/liblangtag-gobject/Makefile.am
@@ -153,6 +153,7 @@
 	$(NULL)
 liblangtag_gobject_la_LDFLAGS =						\
 	$(LDFLAGS)							\
+	-no-undefined							\
 	-version-info $(LT_G_CURRENT):$(LT_G_REVISION):$(LT_G_AGE)	\
 	$(NULL)
 #
--- liblangtag-0.6.7/extensions/Makefile.am.orig	2021-09-27 06:52:04.000000000 +0200
+++ liblangtag-0.6.7/extensions/Makefile.am	2025-08-01 17:02:03.580475200 +0200
@@ -62,6 +62,7 @@
 liblangtag_ext_ldml_t_la_LDFLAGS =		\
 	-avoid-version				\
 	-module					\
+	-no-undefined						\
 	$(NULL)
 #
 liblangtag_ext_ldml_u_la_SOURCES =	\
@@ -73,6 +74,7 @@
 liblangtag_ext_ldml_u_la_LDFLAGS =		\
 	-avoid-version				\
 	-module					\
+	-no-undefined						\
 	$(NULL)
 
 -include $(top_srcdir)/git.mk
