Index: pyorbit-2.14.1/m4/python-module.m4
===================================================================
--- pyorbit-2.14.1.orig/m4/python-module.m4
+++ pyorbit-2.14.1/m4/python-module.m4
@@ -67,12 +67,12 @@ if egrep "^#define Py_ENABLE_SHARED" "${
   PYTHON_LDFLAGS="-no-undefined"
   save_LIBS="$LIBS"
 
-  PYTHON_LIBS="-L${py_prefix}/lib/ -lpython${PYTHON_VERSION}"
+  PYTHON_LIBS="-L${py_prefix}/lib/ -lpython${PYTHON_VERSION} -pthread"
   LIBS="$LIBS $PYTHON_LIBS"
   AC_TRY_LINK_FUNC(Py_Initialize, dnl
          [LIBS="$save_LIBS"; AC_MSG_RESULT([$PYTHON_LIBS]); $1], dnl
 [
-  PYTHON_LIBS="-L${py_prefix}/lib/python${PYTHON_VERSION}/config -lpython${PYTHON_VERSION}"
+  PYTHON_LIBS="-L${py_prefix}/lib/python${PYTHON_VERSION}/config -lpython${PYTHON_VERSION} -pthread"
   LIBS="$save_LIBS $PYTHON_LIBS";
   AC_TRY_LINK_FUNC(Py_Initialize, dnl
          [LIBS="$save_LIBS"; AC_MSG_RESULT([$PYTHON_LIBS]); $1], dnl