--- a/Makefile.am
+++ b/Makefile.am
@@ -295,7 +295,7 @@ endif
 ##
 fs_encode_SOURCES = src/fs_encode.c
 fs_encode_CFLAGS = $(AM_CFLAGS)
-fs_encode_LDFLAGS = $(AM_LDFLAGS) $(CORE_LIBS)
+fs_encode_LDFLAGS = $(AM_LDFLAGS) -lpthread $(CORE_LIBS)
 fs_encode_LDADD = libfreeswitch.la
 
 ##
@@ -303,7 +303,7 @@ fs_encode_LDADD = libfreeswitch.la
 ##
 tone2wav_SOURCES = src/tone2wav.c
 tone2wav_CFLAGS  = $(AM_CFLAGS)
-tone2wav_LDFLAGS = $(AM_LDFLAGS) $(CORE_LIBS)
+tone2wav_LDFLAGS = $(AM_LDFLAGS) -lpthread $(CORE_LIBS)
 tone2wav_LDADD   = libfreeswitch.la
 
 ##