diff --git a/.travis.yml b/.travis.yml
index 7537533a..7d34f845 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,6 +20,8 @@ script:
 - cd bin/
 - file_name_integer="nodemcu_integer_${TRAVIS_TAG}.bin"
 - srec_cat -output ${file_name_integer} -binary 0x00000.bin -binary -fill 0xff 0x00000 0x10000 0x10000.bin -binary -offset 0x10000
+# http://docs.travis-ci.com/user/environment-variables/#Convenience-Variables
+- if [ "$TRAVIS_PULL_REQUEST" != "false" ]; then bash "$TRAVIS_BUILD_DIR"/tools/pr-build.sh; fi
 deploy:
   provider: releases
   api_key:
diff --git a/tools/pr-build.sh b/tools/pr-build.sh
new file mode 100644
index 00000000..c7b310f3
--- /dev/null
+++ b/tools/pr-build.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+set -e
+
+echo "Running PR build (all modules, SSL disabled)"
+(
+cd "$TRAVIS_BUILD_DIR"/app/include || exit
+# uncomment disabled modules e.g. '//#define LUA_USE_MODULES_UCG' -> '#define LUA_USE_MODULES_UCG'
+sed -E -i.bak 's@(//.*)(#define *LUA_USE_MODULES_.*)@\2@g' user_modules.h
+cat user_modules.h
+
+# disable SSL
+sed -i.bak 's@#define CLIENT_SSL_ENABLE@//#define CLIENT_SSL_ENABLE@' user_config.h
+cat user_config.h
+
+# change to "root" directory no matter where the script was started from
+cd "$TRAVIS_BUILD_DIR" || exit
+make clean
+make
+)