diff --git a/include/nlohmann/detail/input/binary_reader.hpp b/include/nlohmann/detail/input/binary_reader.hpp
index 6474b8b059..75a20ed7b8 100644
--- a/include/nlohmann/detail/input/binary_reader.hpp
+++ b/include/nlohmann/detail/input/binary_reader.hpp
@@ -2178,6 +2178,13 @@ class binary_reader
             std::vector<char_int_type> bjdx = {'[', '{', 'S', 'H', 'T', 'F', 'N', 'Z'}; // excluded markers in bjdata optimized type
 
             result.second = get();  // must not ignore 'N', because 'N' maybe the type
+            if (JSON_HEDLEY_UNLIKELY( input_format == input_format_t::bjdata && std::find(bjdx.begin(), bjdx.end(), result.second) != bjdx.end() ))
+            {
+                auto last_token = get_token_string();
+                return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read,
+                                        exception_message(input_format, concat("marker 0x", last_token, " is not a permitted optimized array type"), "type"), nullptr));
+            }
+
             if (JSON_HEDLEY_UNLIKELY(!unexpect_eof(input_format, "type") || (input_format == input_format_t::bjdata && std::find(bjdx.begin(), bjdx.end(), result.second) != bjdx.end() )))
             {
                 return false;
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index d596180c6a..9bd1705332 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -10554,6 +10554,13 @@ class binary_reader
             std::vector<char_int_type> bjdx = {'[', '{', 'S', 'H', 'T', 'F', 'N', 'Z'}; // excluded markers in bjdata optimized type
 
             result.second = get();  // must not ignore 'N', because 'N' maybe the type
+            if (JSON_HEDLEY_UNLIKELY( input_format == input_format_t::bjdata && std::find(bjdx.begin(), bjdx.end(), result.second) != bjdx.end() ))
+            {
+                auto last_token = get_token_string();
+                return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read,
+                                        exception_message(input_format, concat("marker 0x", last_token, " is not a permitted optimized array type"), "type"), nullptr));
+            }
+
             if (JSON_HEDLEY_UNLIKELY(!unexpect_eof(input_format, "type") || (input_format == input_format_t::bjdata && std::find(bjdx.begin(), bjdx.end(), result.second) != bjdx.end() )))
             {
                 return false;
diff --git a/test/src/unit-bjdata.cpp b/test/src/unit-bjdata.cpp
index bc6c52833a..af5d8e6231 100644
--- a/test/src/unit-bjdata.cpp
+++ b/test/src/unit-bjdata.cpp
@@ -2626,6 +2626,11 @@ TEST_CASE("BJData")
             CHECK_THROWS_AS(_ = json::from_bjdata(vU), json::parse_error&);
             CHECK_THROWS_WITH(_ = json::from_bjdata(vU), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData value: unexpected end of input");
             CHECK(json::from_bjdata(vU, true, false).is_discarded());
+
+            std::vector<uint8_t> v1 = {'[', '$', '['};
+            CHECK_THROWS_AS(_ = json::from_bjdata(v1), json::parse_error&);
+            CHECK_THROWS_WITH(_ = json::from_bjdata(v1), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x5B is not a permitted optimized array type");
+            CHECK(json::from_bjdata(v1, true, false).is_discarded());
         }
 
         SECTION("arrays")