diff --git a/ROADMAP.md b/ROADMAP.md
index 4b613cd2..9251bad1 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -52,9 +52,6 @@ functions and the new response function described above.
 
 ### REST
 
-The `known_content_type` callback has no purpose, so it
-is going to be removed.
-
 The documentation for all REST callbacks will be updated
 to describe whether they can have side effects. This will
 allows us to build introspection tools on top of a working
diff --git a/doc/src/guide/rest_handlers.ezdoc b/doc/src/guide/rest_handlers.ezdoc
index 8cdd12e9..1868f0a7 100644
--- a/doc/src/guide/rest_handlers.ezdoc
+++ b/doc/src/guide/rest_handlers.ezdoc
@@ -67,7 +67,6 @@ if it is undefined, moving directly to the next step. Similarly,
 |	generate_etag			`undefined`
 |	is_authorized			`true`
 |	is_conflict				`false`
-|	known_content_type		`true`
 |	known_methods			`[<<"GET">>, <<"HEAD">>, <<"POST">>, <<"PUT">>, <<"PATCH">>, <<"DELETE">>, <<"OPTIONS">>]`
 |	languages_provided		skip
 |	last_modified			`undefined`
diff --git a/doc/src/guide/rest_start.png b/doc/src/guide/rest_start.png
index 7f264642..1f1e312e 100644
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diff --git a/doc/src/guide/rest_start.svg b/doc/src/guide/rest_start.svg
index d75e1cc6..076c6195 100644
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+++ b/doc/src/guide/rest_start.svg
@@ -16,7 +16,7 @@
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@@ -93,7 +93,7 @@
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@@ -727,14 +675,6 @@
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+         y="812.14441">valid_entity_length</tspan></text>
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@@ -949,18 +889,7 @@
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@@ -1101,17 +1030,6 @@
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@@ -1426,18 +1325,7 @@
          sodipodi:role="line"
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-    <text
-       xml:space="preserve"
-       style="font-size:16px;font-style:normal;font-weight:normal;text-align:center;line-height:125%;letter-spacing:0px;word-spacing:0px;text-anchor:middle;fill:#77823c;fill-opacity:1;stroke:none;font-family:Sans;-inkscape-font-specification:Sans"
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-         sodipodi:role="line"
-         id="tspan5373-0"
-         x="524.26172"
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+         y="813.64819">413 request entity too large</tspan></text>
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diff --git a/doc/src/manual/cowboy_rest.ezdoc b/doc/src/manual/cowboy_rest.ezdoc
index cd60566e..f9e938a1 100644
--- a/doc/src/manual/cowboy_rest.ezdoc
+++ b/doc/src/manual/cowboy_rest.ezdoc
@@ -311,17 +311,6 @@ Return whether the put action results in a conflict.
 A `409 Conflict` response will be sent if this function
 returns `true`.
 
-: known_content_type
-
-* Methods: all
-* Value type: boolean()
-* Default value: true
-
-Return whether the content-type is known.
-
-This function determines if the server understands the
-content-type, regardless of its use by the resource.
-
 : known_methods
 
 * Methods: all
diff --git a/src/cowboy_rest.erl b/src/cowboy_rest.erl
index 98c6f3b0..306584a7 100644
--- a/src/cowboy_rest.erl
+++ b/src/cowboy_rest.erl
@@ -155,11 +155,7 @@ forbidden(Req, State) ->
 
 valid_content_headers(Req, State) ->
 	expect(Req, State, valid_content_headers, true,
-		fun known_content_type/2, 501).
-
-known_content_type(Req, State) ->
-	expect(Req, State, known_content_type, true,
-		fun valid_entity_length/2, 415).
+		fun valid_entity_length/2, 501).
 
 valid_entity_length(Req, State) ->
 	expect(Req, State, valid_entity_length, true, fun options/2, 413).