diff --git a/math/primesum/Makefile b/math/primesum/Makefile
index 0f9e589011d6..a929a184236c 100644
--- a/math/primesum/Makefile
+++ b/math/primesum/Makefile
@@ -11,6 +11,8 @@ WWW=		https://github.com/kimwalisch/primesum
 LICENSE=	BSD2CLAUSE
 LICENSE_FILE=	${WRKSRC}/COPYING
 
+BROKEN_i386=	compiler does not support int128_t
+
 USES=		cmake:testing compiler:c++11-lang
 USE_LDCONFIG=	yes