diff --git a/lib/Makefile.am b/lib/Makefile.am
index 245b669b2d..49ddf56773 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -158,7 +158,7 @@ libboinc_la_LIBADD =
 libboinc_crypt_la_SOURCES = crypt.cpp
 libboinc_crypt_la_CFLAGS = $(AM_CFLAGS) $(PICFLAGS) $(PTHREAD_CFLAGS) $(SSL_CFLAGS)
 libboinc_crypt_la_CXXFLAGS = $(AM_CXXFLAGS) $(PICFLAGS) $(PTHREAD_CFLAGS) $(SSL_CXXFLAGS)
-libboinc_crypt_la_LDFLAGS = -L$(libdir) -rpath $(libdir) -static -version-number $(LIBBOINC_VERSION)
+libboinc_crypt_la_LDFLAGS = -L$(libdir) -rpath $(libdir) -static -version-number $(LIBBOINC_VERSION) -lpthread
 libboinc_crypt_la_LIBADD =