diff --git a/lib/libspl/Makefile.am b/lib/libspl/Makefile.am
index eb2377305a..94be416d46 100644
--- a/lib/libspl/Makefile.am
+++ b/lib/libspl/Makefile.am
@@ -45,3 +45,7 @@ libspl_la_LIBADD = \
 libspl_la_LIBADD += $(LIBATOMIC_LIBS) $(LIBCLOCK_GETTIME)
 
 libspl_assert_la_LIBADD = $(BACKTRACE_LIBS) $(LIBUNWIND_LIBS)
+
+if BUILD_FREEBSD
+libspl_assert_la_LIBADD += -lpthread
+endif