diff --git a/TestConfig/GraphBLAS/demo.cc b/TestConfig/GraphBLAS/demo.cc
index 523c5653d3..1cd1073260 100644
--- a/TestConfig/GraphBLAS/demo.cc
+++ b/TestConfig/GraphBLAS/demo.cc
@@ -11,7 +11,10 @@
 
 #include <iostream>
 
-#include "GraphBLAS.h"
+extern "C"
+{
+    #include "GraphBLAS.h"
+}
 
 int main (void)
 {