diff --git a/include/nlohmann/json.hpp b/include/nlohmann/json.hpp
index 7ea86c38c2..5337e53145 100644
--- a/include/nlohmann/json.hpp
+++ b/include/nlohmann/json.hpp
@@ -8456,7 +8456,8 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
             // get reference to parent of JSON pointer ptr
             const auto last_path = ptr.back();
             ptr.pop_back();
-            basic_json& parent = result[ptr];
+            // parent must exist when performing patch add per RFC6902 specs
+            basic_json& parent = result.at(ptr);
 
             switch (parent.m_type)
             {
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index 5800976306..f4407577ba 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -25996,7 +25996,8 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
             // get reference to parent of JSON pointer ptr
             const auto last_path = ptr.back();
             ptr.pop_back();
-            basic_json& parent = result[ptr];
+            // parent must exist when performing patch add per RFC6902 specs
+            basic_json& parent = result.at(ptr);
 
             switch (parent.m_type)
             {
diff --git a/test/src/unit-json_patch.cpp b/test/src/unit-json_patch.cpp
index 95af671986..17299722c0 100644
--- a/test/src/unit-json_patch.cpp
+++ b/test/src/unit-json_patch.cpp
@@ -83,6 +83,14 @@ TEST_CASE("JSON patch")
             CHECK_THROWS_AS(doc2.patch(patch), json::out_of_range&);
             CHECK_THROWS_WITH(doc2.patch(patch),
                               "[json.exception.out_of_range.403] key 'a' not found");
+
+            json doc3 = R"({ "a": {} })"_json;
+            json patch3 = R"([{ "op": "add", "path": "/a/b/c", "value": 1 }])"_json;
+
+            // patch3 should cause an error because "b" does not exist in doc3
+            CHECK_THROWS_AS(doc3.patch(patch3), json::out_of_range&);
+            CHECK_THROWS_WITH(doc3.patch(patch3),
+                              "[json.exception.out_of_range.403] key 'b' not found");
         }
 
         SECTION("4.2 remove")