diff --git a/dumux/common/quad.hh b/dumux/common/quad.hh
index 89d6b7b95a43df51aa7549126ada9b5390520d01..62230d173f5d9c490c8374ad504a194174c0b808 100644
--- a/dumux/common/quad.hh
+++ b/dumux/common/quad.hh
@@ -30,7 +30,10 @@
 
 #include <iostream>
 #include <cmath>
+
+extern "C" {
 #include <quadmath.h>
+}
 
 typedef __float128 quad;