diff --git a/libsysio/include/sysio-cmn.h b/libsysio/include/sysio-cmn.h
index ed9a2c114046e386376ebbeff3648de8ecb91766..3fd283ee43527499fb49a91cd01d9f08784290b7 100644
--- a/libsysio/include/sysio-cmn.h
+++ b/libsysio/include/sysio-cmn.h
@@ -98,14 +98,14 @@ struct iovec;
 /*
  * SYSIO name label macros
  */
-#ifndef SYIO_INTERFACE_NAME
+#ifndef SYSIO_INTERFACE_NAME
 #ifdef SYSIO_LABEL_NAMES
 #define SYSIO_INTERFACE_NAME(x) \
 	PREPEND(SYSIO_LABEL_NAMES, x)
 #else
 #define SYSIO_INTERFACE_NAME(x) x
 #endif /* SYSIO_LABEL_NAMES */
-#endif /* SYSIO_INTERFACE_NAME */
+#endif /* !SYSIO_INTERFACE_NAME */
 
 /* for debugging */
 #if 0