diff --git a/README b/README
index 58b09e7..87a6194 100644
--- a/README
+++ b/README
@@ -7,7 +7,7 @@ V8js is a PHP extension for Google's V8 Javascript engine
Minimum requirements
--------------------
-- V8 library version 2.5.8 (trunk)
+- V8 library version >= 3.17.11 (trunk)
- PHP 5.3.3+ (non-ZTS build preferred)
Note: V8 engine is not natively thread safe and this extension
diff --git a/README.md b/README.md
index 3261934..7b9937c 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ Minimum requirements
V8 is Google's open source Javascript engine.
V8 is written in C++ and is used in Google Chrome, the open source browser from Google.
V8 implements ECMAScript as specified in ECMA-262, 5th edition.
- This extension makes use of V8 isolates to ensure separation between multiple V8Js instances, hence the need for 3.2.4 or above.
+ This extension makes use of V8 isolates to ensure separation between multiple V8Js instances, hence the need for 3.17.11 or above. (See .)
- PHP 5.3.3+
diff --git a/config.m4 b/config.m4
index 6059de0..1e7a30d 100644
--- a/config.m4
+++ b/config.m4
@@ -63,6 +63,10 @@ LDFLAGS=$old_LDFLAGS
set $ac_cv_v8_version
IFS=$ac_IFS
V8_API_VERSION=`expr [$]1 \* 1000000 + [$]2 \* 1000 + [$]3`
+ if test "$V8_API_VERSION" -lt 3017011 ; then
+ # see https://github.com/preillyme/v8js/issues/12
+ AC_MSG_ERROR([libv8 must be version 3.17.11 or greater])
+ fi
AC_DEFINE_UNQUOTED([PHP_V8_API_VERSION], $V8_API_VERSION, [ ])
AC_DEFINE_UNQUOTED([PHP_V8_VERSION], "$ac_cv_v8_version", [ ])
fi