diff --git a/README b/README
index 701207fa8..09eba576f 100644
--- a/README
+++ b/README
@@ -283,12 +283,14 @@ The configuration file needs to set the following parameters:
     51degrees-data-file           path to the pattern or trie data file
     51degrees-property-name-list  list of 51Degrees properties to detect
     51degrees-property-separator  separator to use between values
+    51degrees-cache-size          LRU-based cache size (disabled by default)
 
 The following is an example of the settings for Pattern.
 
     51degrees-data-file '51D_REPO_PATH'/data/51Degrees-Lite.dat
     51degrees-property-name-list IsTablet DeviceType IsMobile
     51degrees-property-separator ,
+    51degrees-cache-size 10000
 
 HAProxy needs a way to pass device information to the backend servers. This is
 done by using the 51d converter, which intercepts the User-Agent header and
diff --git a/doc/configuration.txt b/doc/configuration.txt
index c4c3d23ad..05f76521f 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -543,6 +543,7 @@ The following keywords are supported in the "global" section :
    - 51degrees-data-file
    - 51degrees-property-name-list
    - 51degrees-property-separator
+   - 51degrees-cache-size
 
  * Performance tuning
    - max-spread-checks
@@ -875,7 +876,7 @@ description <text>
   The path of the 51Degrees data file to provide device detection services. The
   file should be unzipped and accessible by HAProxy with relevavnt permissions.
 
-  Please note that this options is only available when haproxy has been
+  Please note that this option is only available when haproxy has been
   compiled with USE_51DEGREES.
 
 51degrees-property-name-list [<string>]
@@ -883,14 +884,22 @@ description <text>
   of names is available on the 51Degrees website:
   https://51degrees.com/resources/property-dictionary
 
-  Please note that this options is only available when haproxy has been
+  Please note that this option is only available when haproxy has been
   compiled with USE_51DEGREES.
 
 51degrees-property-separator <char>
   A char that will be appended to every property value in a response header
   containing 51Degrees results. If not set that will be set as ','.
 
-  Please note that this options is only available when haproxy has been
+  Please note that this option is only available when haproxy has been
+  compiled with USE_51DEGREES.
+
+51degrees-cache-size <number>
+  Sets the size of the 51Degrees converter cache to <number> entries. This
+  is an LRU cache which reminds previous device detections and their results.
+  By default, this cache is disabled.
+
+  Please note that this option is only available when haproxy has been
   compiled with USE_51DEGREES.