diff --git a/package/libpthsem/libpthsem.mk b/package/libpthsem/libpthsem.mk
index f9f6f71813..b8a3d7d561 100644
--- a/package/libpthsem/libpthsem.mk
+++ b/package/libpthsem/libpthsem.mk
@@ -13,6 +13,20 @@ LIBPTHSEM_AUTORECONF = YES
 LIBPTHSEM_INSTALL_STAGING = YES
 LIBPTHSEM_CONFIG_SCRIPTS = pthsem-config
 
+# Force the setjmp/longjmp detection, because the test being done in
+# the AC_CHECK_SJLJ macro is not cross-compilation safe: it checks the
+# running kernel with 'uname -r', and checks the C library version by
+# looking at /usr/include/features.h. In terms of kernel version, it
+# assumes any version later than 2.2.x is fine, except that it doesn't
+# recognize 4.x as a valid kernel version, recognizing such systems as
+# "braindead" and therefore falling back to the 'sjljlx' value for
+# ac_cv_check_sjlj. In terms of C library version, it wants
+# __GLIBC_MINOR to be at least 1. Since both conditions are true for
+# all Buildroot systems, we can simply force the setjmp/longjmp
+# detection to ssjlj.
+LIBPTHSEM_CONF_ENV += \
+	ac_cv_check_sjlj=ssjlj
+
 ifeq ($(BR2_PACKAGE_LIBPTHSEM_COMPAT),y)
 LIBPTHSEM_CONF_OPTS += --enable-compat
 LIBPTHSEM_CONFIG_SCRIPTS += pth-config