diff --git a/Makefile.am b/Makefile.am
index bedccbf..7ed0b17 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -167,7 +167,7 @@ endif #end hpux
 #    If any interfaces have been added since the last public release, then increment age.
 #    If any interfaces have been removed or changed since the last public release, then set age to 0. 
 
-SDS_LDFLAGS = $(NSPR_LINK) -version-info 0:0:0
+SDS_LDFLAGS = $(NSPR_LINK) -version-info 0:0:0 -lpthread
 NUNCSTANS_LDFLAGS = $(NSPR_LINK) $(EVENT_LINK) -version-info 1:0:1
 SLAPD_LDFLAGS = -version-info 1:0:1