diff --git a/.Rbuildignore b/.Rbuildignore
index e24f9d9..df5eab2 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -5,10 +5,9 @@
 ^NEWS\.md$
 ^README\.md$
 ^CONDUCT\.md$
-^README\.Rmd$
 ^README-.*\.png$
 ^\.Rhistory$
 ^cran-comments\.md$
 ^\.travis\.yml$
 ^docs$
-^map\.png$
\ No newline at end of file
+^map\.png$
diff --git a/DESCRIPTION b/DESCRIPTION
index c57b905..acbd7be 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -15,6 +15,7 @@ License: MIT + file LICENSE
 URL: https://github.com/hrbrmstr/iptools
 BugReports: https://github.com/hrbrmstr/iptools/issues
 NeedsCompilation: yes
+SystemRequirements: C++11
 Depends:
     R (>= 3.0.0)
 Suggests:
diff --git a/cran-comments.md b/cran-comments.md
index aaf6e97..6431553 100644
--- a/cran-comments.md
+++ b/cran-comments.md
@@ -1,21 +1,16 @@
 ## Test environments
-- It has been tested on:
-
-  * a standalone Windows systems (release)
-  * 2 Linux systems (devel)
-  * 2 OS X systems (devel & release)
-  * WinBuilder (devel & release)
+* local OS X install, R 3.5.1
+* ubuntu 14.04 (on travis-ci), R 3.5.1
+* win-builder (devel and release)
 
 ## R CMD check results
-- There were no ERRORs or WARNINGs. 
-- The NOTE - "Note: found 12 marked UTF-8 strings" are necessary (and have been
-  NOTEd in every release to-date)
 
-## Other
+0 errors | 0 warnings | 0 note
+
+* This is a maintenance release
+
+------
 
-iptools 0.4.0
-=============
-* bug fix for `ip_in_range` always returning TRUE for /32 ranges (@tdsmith)
-* enhanced `range_boundaries()` to include more columns in output
-* added `country_ranges()` which enables obtaining all the IPv4 ranges
-  "assigned" within a country.
+* Adds C registration
+* Fixes major CRAN warnings over strncpy
+* Adds new functions
\ No newline at end of file
diff --git a/src/Makevars b/src/Makevars
index aab7e6f..15ba676 100644
--- a/src/Makevars
+++ b/src/Makevars
@@ -1 +1,3 @@
+CXX_STD = CXX11
+PKG_CXXFLAGS =
 PKG_LIBS =
\ No newline at end of file
diff --git a/src/Makevars.win b/src/Makevars.win
index 6b746bd..3c64445 100755
--- a/src/Makevars.win
+++ b/src/Makevars.win
@@ -1 +1,3 @@
+CXX_STD = CXX11
+PKG_CXXFLAGS =
 PKG_LIBS = -lwsock32 -lws2_32