diff --git a/src/test/nbt_tags.cpp b/src/test/nbt_tags.cpp
index 79e135c..90bd1b2 100644
--- a/src/test/nbt_tags.cpp
+++ b/src/test/nbt_tags.cpp
@@ -773,11 +773,16 @@ int main(){
     NBT::Tag::Int8* pointer_2_1 = new NBT::Tag::Int8("entry_2_1", 28);
     NBT::Tag::Int8* pointer_2_2 = new NBT::Tag::Int8("entry_2_2", 45);
     NBT::Tag::Int8* pointer_2_3 = new NBT::Tag::Int8("entry_2_3", 78);
+    NBT::Tag::Int8* pointer_invalid_0 = new NBT::Tag::Int8("ayya", 78);
+    NBT::Tag::Int16* pointer_invalid_1 = new NBT::Tag::Int16("ellohhh", 78);
     std::vector<NBT::Tag::Generic*> listDataVector;
     listDataVector.push_back(pointer_2_0);
     listDataVector.push_back(pointer_2_1);
     listDataVector.push_back(pointer_2_2);
     listDataVector.push_back(pointer_2_3);
+    std::vector<NBT::Tag::Generic*> invalidListDataVector;
+    invalidListDataVector.push_back(pointer_invalid_0);
+    invalidListDataVector.push_back(pointer_invalid_1);
 
     NBT::Tag::List list_0 = NBT::Tag::List();
     ASSERT(list_0.serialize(&vector).isError);
@@ -792,8 +797,9 @@ int main(){
     NBT::Tag::Int16* pointer_invalid = new NBT::Tag::Int16("invalid", 400);
     resultError = list_1.appendPointer(pointer_invalid);
     ASSERT(resultError.isError && resultError.errorCode == ErrorCodes::INVALID_TYPE);
-    //TODO: Check that constructing with a vector of mixed tags
-    // results in a clearly defined failure mode (issue #60)
+    ErrorOr<NBT::Tag::List*> invalid_list_or_error = NBT::Tag::List::constructWithData("list_invalid", invalidListDataVector);
+    ASSERT(invalid_list_or_error.isError);
+    ASSERT(invalid_list_or_error.errorCode == ErrorCodes::MIXED_TYPES);
     ErrorOr<NBT::Tag::List*> list_2_or_error = NBT::Tag::List::constructWithData("list_2", listDataVector);
     ASSERT(!list_2_or_error.isError);
     NBT::Tag::List* list_2 = list_2_or_error.value;
@@ -886,12 +892,21 @@ int main(){
     compoundDataVector.push_back(new NBT::Tag::Int16("will be deleted", 0x1337));
     compoundDataVector.push_back(new NBT::Tag::Int16("1", 0x1337));
     compoundDataVector.push_back(new NBT::Tag::String("2", "Hello World!"));
+    std::vector<NBT::Tag::Generic*> invalidCompoundDataVector;
+    invalidCompoundDataVector.push_back(new NBT::Tag::End());
+    invalidCompoundDataVector.push_back(new NBT::Tag::End());
+    std::vector<NBT::Tag::Generic*> compoundDataVectorWithEnd;
+    compoundDataVectorWithEnd.push_back(new NBT::Tag::Int8("eeee", 25));
+    compoundDataVectorWithEnd.push_back(new NBT::Tag::End());
 
     NBT::Tag::Compound compound_0 = NBT::Tag::Compound();
     compound_0.name = "compound_0";
     NBT::Tag::Compound compound_1 = NBT::Tag::Compound("compound_1");
-    //TODO: Check that constructing with a vector containing an end tag that
-    // isn’t at the end results in a clearly defined failure mode (issue #60)
+    ErrorOr<NBT::Tag::Compound*> invalid_compound_or_error = NBT::Tag::Compound::constructWithData("iiiiii", invalidCompoundDataVector);
+    ASSERT(invalid_compound_or_error.isError);
+    ASSERT(invalid_compound_or_error.errorCode == ErrorCodes::NOT_ALLOWED);
+    ErrorOr<NBT::Tag::Compound*> alternate_compound_or_error = NBT::Tag::Compound::constructWithData("iiiiii", compoundDataVectorWithEnd);
+    ASSERT(!alternate_compound_or_error.isError);
     ErrorOr<NBT::Tag::Compound*> compound_2_or_error = NBT::Tag::Compound::constructWithData("compound_2", compoundDataVector);
     ASSERT(!compound_2_or_error.isError);
     NBT::Tag::Compound* compound_2 = compound_2_or_error.value;