diff --git a/config/environments/development.js.example b/config/environments/development.js.example
index 37c09037..760a7840 100644
--- a/config/environments/development.js.example
+++ b/config/environments/development.js.example
@@ -101,6 +101,17 @@ var config = {
           // wasted time.
           metatile: 2,
 
+          // tilelive-mapnik uses an internal cache to store tiles/grids
+          // generated when using metatile. This options allow to tune
+          // the behaviour for that internal cache.
+          metatileCache: {
+              // Time an object must stay in the cache until is removed
+              ttl: 0,
+              // Whether an object must be removed after the first hit
+              // Usually you want to use `true` here when ttl>0.
+              deleteOnHit: false
+          },
+
           // Override metatile behaviour depending on the format
           formatMetatile: {
               png: 2,
diff --git a/config/environments/production.js.example b/config/environments/production.js.example
index 64e0e26e..2e31ddf6 100644
--- a/config/environments/production.js.example
+++ b/config/environments/production.js.example
@@ -95,6 +95,17 @@ var config = {
           // wasted time.
           metatile: 2,
 
+          // tilelive-mapnik uses an internal cache to store tiles/grids
+          // generated when using metatile. This options allow to tune
+          // the behaviour for that internal cache.
+          metatileCache: {
+              // Time an object must stay in the cache until is removed
+              ttl: 0,
+              // Whether an object must be removed after the first hit
+              // Usually you want to use `true` here when ttl>0.
+              deleteOnHit: false
+          },
+
           // Override metatile behaviour depending on the format
           formatMetatile: {
               png: 2,
diff --git a/config/environments/staging.js.example b/config/environments/staging.js.example
index 05589ce7..941083bd 100644
--- a/config/environments/staging.js.example
+++ b/config/environments/staging.js.example
@@ -95,6 +95,17 @@ var config = {
           // wasted time.
           metatile: 2,
 
+          // tilelive-mapnik uses an internal cache to store tiles/grids
+          // generated when using metatile. This options allow to tune
+          // the behaviour for that internal cache.
+          metatileCache: {
+              // Time an object must stay in the cache until is removed
+              ttl: 0,
+              // Whether an object must be removed after the first hit
+              // Usually you want to use `true` here when ttl>0.
+              deleteOnHit: false
+          },
+
           // Override metatile behaviour depending on the format
           formatMetatile: {
               png: 2,
diff --git a/config/environments/test.js.example b/config/environments/test.js.example
index 1d8ea9da..65cce732 100644
--- a/config/environments/test.js.example
+++ b/config/environments/test.js.example
@@ -95,6 +95,17 @@ var config = {
           // wasted time.
           metatile: 2,
 
+          // tilelive-mapnik uses an internal cache to store tiles/grids
+          // generated when using metatile. This options allow to tune
+          // the behaviour for that internal cache.
+          metatileCache: {
+              // Time an object must stay in the cache until is removed
+              ttl: 0,
+              // Whether an object must be removed after the first hit
+              // Usually you want to use `true` here when ttl>0.
+              deleteOnHit: false
+          },
+
           // Override metatile behaviour depending on the format
           formatMetatile: {
               png: 2,