diff --git a/src/server/internalServer.cpp b/src/server/internalServer.cpp
index 876a5f7f6..f13b9e23a 100644
--- a/src/server/internalServer.cpp
+++ b/src/server/internalServer.cpp
@@ -462,6 +462,11 @@ std::string noSearchResultsMsg()
   return "The fulltext search engine is not available for this content.";
 }
 
+ParameterizedMessage invalidRawAccessMsg(const std::string& dt)
+{
+  return ParameterizedMessage("invalid-raw-data-type", { {"DATATYPE", dt} });
+}
+
 ParameterizedMessage nonParameterizedMessage(const std::string& msgId)
 {
   return ParameterizedMessage(msgId, {});
@@ -924,10 +929,9 @@ std::unique_ptr<Response> InternalServer::handle_raw(const RequestContext& reque
   }
 
   if (kind != "meta" && kind!= "content") {
-    const std::string error_details = kind + " is not a valid request for raw content.";
     return HTTP404HtmlResponse(*this, request)
            + urlNotFoundMsg
-           + error_details;
+           + invalidRawAccessMsg(kind);
   }
 
   std::shared_ptr<zim::Archive> archive;
diff --git a/static/i18n/en.json b/static/i18n/en.json
index 6c34ec729..4772302fe 100644
--- a/static/i18n/en.json
+++ b/static/i18n/en.json
@@ -9,4 +9,5 @@
 	, "url-not-found" : "The requested URL \"{{url}}\" was not found on this server."
 	, "suggest-search" : "Make a full text search for <a href=\"{{{SEARCH_URL}}}\">{{PATTERN}}</a>"
 	, "random-article-failure" :  "Oops! Failed to pick a random article :("
+	, "invalid-raw-data-type" : "{{DATATYPE}} is not a valid request for raw content."
 }
diff --git a/static/i18n/qqq.json b/static/i18n/qqq.json
index cbf41ffaf..34f57dd01 100644
--- a/static/i18n/qqq.json
+++ b/static/i18n/qqq.json
@@ -10,4 +10,5 @@
 	, "url-not-found" : "Error text about wrong URL for an HTTP 404 error"
 	, "suggest-search" : "Suggest a search when the URL points to a non existing article"
 	, "random-article-failure" :  "Failure of the random article selection procedure"
+	, "invalid-raw-data-type" : "Invalid DATATYPE was used with the /raw endpoint (/raw/<book>/DATATYPE/...); allowed values are 'meta' and 'content'"
 }