diff --git a/src/json-validator.cpp b/src/json-validator.cpp
index 2800d9d..94691a2 100644
--- a/src/json-validator.cpp
+++ b/src/json-validator.cpp
@@ -172,7 +172,10 @@ public:
 		if (unresolved != file.unresolved.end())
 			schema::make(value, this, {}, {{new_uri}});
 		else // no, nothing ref'd it, keep for later
-			file.unknown_keywords[fragment] = value;
+			// could use fragment here, but better not to: if key is an integer the pointer will be interpreted as
+			// an array. This cannot be the case here, so we force using key as a string when storing the
+			// unknown_keyword-schema.
+			file.unknown_keywords[uri.pointer()][key] = value;
 
 		// recursively add possible subschemas of unknown keywords
 		if (value.type() == json::value_t::object)
diff --git a/test/issue-143/CMakeLists.txt b/test/issue-143/CMakeLists.txt
new file mode 100644
index 0000000..1cc2365
--- /dev/null
+++ b/test/issue-143/CMakeLists.txt
@@ -0,0 +1,13 @@
+add_test_simple_schema(Issue::143-1
+                       ${CMAKE_CURRENT_SOURCE_DIR}/schema.json
+                       ${CMAKE_CURRENT_SOURCE_DIR}/instance-fail-1.json)
+add_test_simple_schema(Issue::143-a
+                       ${CMAKE_CURRENT_SOURCE_DIR}/schema.json
+                       ${CMAKE_CURRENT_SOURCE_DIR}/instance-fail-a.json)
+add_test_simple_schema(Issue::143-ok
+                       ${CMAKE_CURRENT_SOURCE_DIR}/schema.json
+                       ${CMAKE_CURRENT_SOURCE_DIR}/instance.json)
+
+set_tests_properties(Issue::143-1 Issue::143-a
+                     PROPERTIES
+                     WILL_FAIL 1)
diff --git a/test/issue-143/instance-fail-1.json b/test/issue-143/instance-fail-1.json
new file mode 100644
index 0000000..7eefb69
--- /dev/null
+++ b/test/issue-143/instance-fail-1.json
@@ -0,0 +1,4 @@
+{
+    "ref1": "a",
+    "refa": "a"
+}
diff --git a/test/issue-143/instance-fail-a.json b/test/issue-143/instance-fail-a.json
new file mode 100644
index 0000000..67f7c5e
--- /dev/null
+++ b/test/issue-143/instance-fail-a.json
@@ -0,0 +1,4 @@
+{
+    "ref1": 12,
+    "refa": 12
+}
diff --git a/test/issue-143/instance.json b/test/issue-143/instance.json
new file mode 100644
index 0000000..d2d55e6
--- /dev/null
+++ b/test/issue-143/instance.json
@@ -0,0 +1,4 @@
+{
+    "ref1": 12,
+    "refa": "a"
+}
diff --git a/test/issue-143/schema.json b/test/issue-143/schema.json
new file mode 100644
index 0000000..4a4503f
--- /dev/null
+++ b/test/issue-143/schema.json
@@ -0,0 +1,21 @@
+{
+    "type": "object",
+
+    "properties": {
+        "unknown_keyword_storage": {
+            "1": {
+                "type": "number"
+            },
+            "a": {
+                "type": "string"
+            }
+        },
+        "ref1": {
+            "$ref": "#/properties/unknown_keyword_storage/1"
+        },
+        "refa": {
+            "$ref": "#/properties/unknown_keyword_storage/a"
+        }
+    },
+    "additionalProperties": false
+}