diff --git a/doc/REST-interface.md b/doc/REST-interface.md
--- a/doc/REST-interface.md
+++ b/doc/REST-interface.md
@@ -29,7 +29,7 @@
 Given a block hash: returns a block, in binary, hex-encoded binary or JSON formats.
 Responds with 404 if the block doesn't exist.
 
-The HTTP request and response are both handled entirely in-memory, thus making maximum memory usage at least 2.66MB (1 MB max block, plus hex encoding) per request.
+The HTTP request and response are both handled entirely in-memory.
 
 With the /notxdetails/ option JSON response will only contain the transaction hash instead of the complete transaction details. The option only affects the JSON response.
 
diff --git a/src/rest.cpp b/src/rest.cpp
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -225,8 +225,9 @@
             return true;
         }
         default: {
-            return RESTERR(req, HTTP_NOT_FOUND,
-                           "output format not found (available: .bin, .hex)");
+            return RESTERR(
+                req, HTTP_NOT_FOUND,
+                "output format not found (available: .bin, .hex, .json)");
         }
     }
 }