---- ../cln-1.3.4/src/base/low/cl_low_mul.cc 2011-04-08 23:06:30.000000000 +0200
-+++ ./src/base/low/cl_low_mul.cc 2017-01-15 18:42:11.755489083 +0100
+--- ../cln-1.3.4/src/base/low/cl_low_mul.cc 2011-04-08 21:06:30.000000000 +0000
++++ ./src/base/low/cl_low_mul.cc 2017-01-17 23:08:39.856001383 +0000
+@@ -10,11 +10,11 @@
+ // Implementation.
+
+ #ifdef NEED_VAR_mulu32_high
+-uint32 mulu32_high;
++extern "C" { uint32 mulu32_high; }
+ #endif
+
+ #ifdef NEED_FUNCTION_mulu32_
+-uint32 mulu32_high;
++extern "C" { uint32 mulu32_high; }
+ namespace cln {
+ uint32 mulu32_ (uint32 x, uint32 y)
+ {