diff --git a/configure.ac b/configure.ac
index a00b2a1..5198d35 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7,7 +7,7 @@ LT_INIT
 AC_PROG_CC
 AC_PROG_CC_STDC
 
-AC_CHECK_HEADERS([stdlib.h string.h sys/time.h stdint.h])
+AC_CHECK_HEADERS([stdlib.h string.h sys/time.h stdint.h pthread.h])
 
 PKG_CHECK_MODULES(CHECK,[check >= 0.9.4],:,[
   ifdef([AM_PATH_CHECK],
diff --git a/src/Makefile.am b/src/Makefile.am
index 6616a97..826792f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,6 +1,6 @@
 lib_LTLIBRARIES = libr3.la
 # lib_LIBRARIES = libr3.a
-libr3_la_SOURCES = node.c edge.c str.c token.c zmalloc.c
+libr3_la_SOURCES = node.c edge.c str.c token.c zmalloc.c workers.c
 # libr3_la_LDFLAGS = -export-symbols-regex '^r3_|^match_'
 
 libr3_la_LIBADD=$(DEPS_LIBS)