diff --git a/net/ccnx/Portfile b/net/ccnx/Portfile
index adcb7bd..6766cfb 100644
--- a/net/ccnx/Portfile
+++ b/net/ccnx/Portfile
@@ -66,7 +66,7 @@
                         BUILD_APPS=false \
 
 configure.cflags        -DCCNX_DIR=\\\"${ccnxdir}\\\" \
-                        -O2
+                        -O2 -std=c99
 
 build.env-append        OPENSSL_CFLAGS=-I${prefix}/include \
                         OPENSSL_LIBS=-L${prefix}/lib \