diff --git a/external/external_build.cmake b/external/external_build.cmake
index a140aba..df13071 100644
--- a/external/external_build.cmake
+++ b/external/external_build.cmake
@@ -59,6 +59,7 @@ find_library(ZLIB_LIBRARY z)
 find_library(DL_LIBRARY dl)
 
 SET(CONFIGURE_CPP_FLAGS "${EXTRA_CPP_FLAGS}")
+SET(CONFIGURE_LD_FLAGS "$ENV{LDFLAGS}")
 string(REPLACE ":" ";" OUT_LIBRARY_PATH "$ENV{LIBRARY_PATH}")
 foreach(P ${OUT_LIBRARY_PATH})
   SET(CONFIGURE_LD_FLAGS "${CONFIGURE_LD_FLAGS} -L${P}")