diff --git a/test/src/unit-class_parser.cpp b/test/src/unit-class_parser.cpp
index 2d2929ee7..f3d30690c 100644
--- a/test/src/unit-class_parser.cpp
+++ b/test/src/unit-class_parser.cpp
@@ -1620,7 +1620,7 @@ TEST_CASE("parser class")
 
         SECTION("from std::array")
         {
-            std::array<uint8_t, 5> v { {'t', 'r', 'u', 'e'} };
+            std::array<uint8_t, 4> v { {'t', 'r', 'u', 'e'} };
             json j;
             json::parser(nlohmann::detail::input_adapter(std::begin(v), std::end(v))).parse(true, j);
             CHECK(j == json(true));
diff --git a/test/src/unit-deserialization.cpp b/test/src/unit-deserialization.cpp
index f92241ff9..875147f8b 100644
--- a/test/src/unit-deserialization.cpp
+++ b/test/src/unit-deserialization.cpp
@@ -358,7 +358,7 @@ TEST_CASE("deserialization")
 
             SECTION("from std::array")
             {
-                std::array<uint8_t, 5> v { {'t', 'r', 'u', 'e'} };
+                std::array<uint8_t, 4> v { {'t', 'r', 'u', 'e'} };
                 CHECK(json::parse(v) == json(true));
                 CHECK(json::accept(v));
 
@@ -453,7 +453,7 @@ TEST_CASE("deserialization")
 
             SECTION("from std::array")
             {
-                std::array<uint8_t, 5> v { {'t', 'r', 'u', 'e'} };
+                std::array<uint8_t, 4> v { {'t', 'r', 'u', 'e'} };
                 CHECK(json::parse(std::begin(v), std::end(v)) == json(true));
                 CHECK(json::accept(std::begin(v), std::end(v)));