diff --git a/JsonArray.cpp b/JsonArray.cpp
index f2e1bfae..8a071f6c 100644
--- a/JsonArray.cpp
+++ b/JsonArray.cpp
@@ -9,7 +9,7 @@
 JsonArray::JsonArray(char* json, jsmntok_t* tokens)
 : JsonObjectBase(json, tokens)
 {
-	if (tokens[0].type != JSMN_ARRAY)
+	if (tokens == 0 || tokens[0].type != JSMN_ARRAY)
 		makeInvalid();
 }
 
diff --git a/JsonHashTable.cpp b/JsonHashTable.cpp
index ee7bc0c2..1e1e0c6b 100644
--- a/JsonHashTable.cpp
+++ b/JsonHashTable.cpp
@@ -11,7 +11,7 @@
 JsonHashTable::JsonHashTable(char* json, jsmntok_t* tokens)
 : JsonObjectBase(json, tokens)
 {
-	if (tokens[0].type != JSMN_OBJECT)
+	if (tokens == 0 || tokens[0].type != JSMN_OBJECT)
 		makeInvalid();
 }