diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..3960bb1
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,18 @@
+language: c
+
+sudo: false
+
+matrix:
+  include:
+    - os: linux
+      addons:
+        apt:
+          packages: [ 'protobuf-compiler', 'libprotobuf-dev' ]
+
+
+install:
+ - make
+
+script:
+ - echo '{"type":"Feature","properties":{},"geometry":{"type":"Point","coordinates":[0,0]}}' > test.json
+ - ./tippecanoe -o test.mbtiles test.json
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 52a6daa..6ed8a05 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 1.5.1
+
+* Fix internal error when number of CPUs is not a power of 2
+* Add missing #include
+
 ## 1.5.0
 
 * Base zoom for dot-dropping can be specified independently of
diff --git a/README.md b/README.md
index 4f71c88..3ad7f94 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,8 @@ tippecanoe
 Builds [vector tilesets](https://www.mapbox.com/developers/vector-tiles/) from large collections of [GeoJSON](http://geojson.org/)
 features. This is a tool for [making maps from huge datasets](MADE_WITH.md).
 
+[![Build Status](https://travis-ci.org/mapbox/tippecanoe.svg)](https://travis-ci.org/mapbox/tippecanoe)
+
 Intent
 ------
 
diff --git a/geojson.c b/geojson.c
index 8544027..5378a92 100644
--- a/geojson.c
+++ b/geojson.c
@@ -71,6 +71,9 @@ void init_cpus() {
 		CPUS = 1;
 	}
 
+	// Round down to a power of 2
+	CPUS = 1 << (int) (log(CPUS) / log(2));
+
 	TEMP_FILES = 64;
 	struct rlimit rl;
 	if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
diff --git a/tile.cc b/tile.cc
index 6fe6509..f13ed6c 100644
--- a/tile.cc
+++ b/tile.cc
@@ -17,6 +17,7 @@
 #include <math.h>
 #include <sqlite3.h>
 #include <pthread.h>
+#include <errno.h>
 #include "vector_tile.pb.h"
 #include "geometry.hh"
 
diff --git a/version.h b/version.h
index 955f192..21c9cfb 100644
--- a/version.h
+++ b/version.h
@@ -1 +1 @@
-#define VERSION "tippecanoe v1.5.0\n"
+#define VERSION "tippecanoe v1.5.1\n"