diff --git a/src/rest.cpp b/src/rest.cpp
index 65033c6c96..eb661c94c6 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -195,7 +195,7 @@ static bool rest_headers(const std::any& context,
 
     const auto parsed_count{ToIntegral<size_t>(path[0])};
     if (!parsed_count.has_value() || *parsed_count < 1 || *parsed_count > MAX_REST_HEADERS_RESULTS) {
-        return RESTERR(req, HTTP_BAD_REQUEST, strprintf("Header count out of acceptable range (1-%u): %s",  MAX_REST_HEADERS_RESULTS, path[0]));
+        return RESTERR(req, HTTP_BAD_REQUEST, strprintf("Header count is invalid or out of acceptable range (1-%u): %s", MAX_REST_HEADERS_RESULTS, path[0]));
     }
 
     std::string hashStr = path[1];
@@ -371,7 +371,7 @@ static bool rest_filter_header(const std::any& context, HTTPRequest* req, const
 
     const auto parsed_count{ToIntegral<size_t>(uri_parts[1])};
     if (!parsed_count.has_value() || *parsed_count < 1 || *parsed_count > MAX_REST_HEADERS_RESULTS) {
-        return RESTERR(req, HTTP_BAD_REQUEST, strprintf("Header count out of acceptable range (1-%u): %s",  MAX_REST_HEADERS_RESULTS, uri_parts[1]));
+        return RESTERR(req, HTTP_BAD_REQUEST, strprintf("Header count is invalid or out of acceptable range (1-%u): %s", MAX_REST_HEADERS_RESULTS, uri_parts[1]));
     }
 
     std::vector<const CBlockIndex*> headers;
diff --git a/test/functional/interface_rest.py b/test/functional/interface_rest.py
index 9cb452e9c0..8f6743d97c 100755
--- a/test/functional/interface_rest.py
+++ b/test/functional/interface_rest.py
@@ -279,7 +279,7 @@ class RESTTest (BitcoinTestFramework):
         # Test number parsing
         for num in ['5a', '-5', '0', '2001', '99999999999999999999999999999999999']:
             assert_equal(
-                bytes(f'Header count out of acceptable range (1-2000): {num}\r\n', 'ascii'),
+                bytes(f'Header count is invalid or out of acceptable range (1-2000): {num}\r\n', 'ascii'),
                 self.test_rest_request(f"/headers/{num}/{bb_hash}", ret_type=RetType.BYTES, status=400),
             )