diff --git a/src/lib/nbt.cpp b/src/lib/nbt.cpp
index be63d68..26ad964 100644
--- a/src/lib/nbt.cpp
+++ b/src/lib/nbt.cpp
@@ -375,6 +375,8 @@ namespace NBT {
         // one that is applicable to the situation (for example replace
         // OUT_OF_RANGE with OVERRUN where appropriate)
         //
+        // The total size in bytes
+        //
         // Does not work for compound tags and lists. This is an intended
         // feature as compound tags and lists need to be dealt with
         // separately to avoid unnecessarily long and complex code.
@@ -386,7 +388,7 @@ namespace NBT {
         // contents requires special attention anyway due the tag headers
         // of contained tags being absent so they may as well get their
         // own function for this as well.
-        ErrorOr<uint64_t> nextTagTotalSize(uint8_t data[], uint64_t dataSize, uint64_t currentPosition) {
+        ErrorOr<uint64_t> totalTagSize(uint8_t data[], uint64_t dataSize, uint64_t currentPosition) {
             uint8_t nextTag;
             if (dataSize <= currentPosition) {
                 return ErrorOr<uint64_t>(true, ErrorCodes::OVERRUN);
@@ -454,7 +456,10 @@ namespace NBT {
         //FIXME: instead of blindly passing the error code upwards, choose
         // one that is applicable to the situation (for example replace
         // OUT_OF_RANGE with OVERRUN where appropriate)
-        ErrorOr<int32_t> nextTagDataLength(uint8_t data[], uint64_t dataSize, uint64_t currentPosition){
+        //
+        // Length is the number of stored elements, not to be confused with size
+        // which is the size in bytes.
+        ErrorOr<int32_t> containedDataLength(uint8_t data[], uint64_t dataSize, uint64_t currentPosition){
 
             uint8_t nextTag;
             if (dataSize <= currentPosition) {
@@ -496,6 +501,8 @@ namespace NBT {
                     return ErrorOr<int32_t>((int32_t) stringSize.value);
                 }
                 case TagType::LIST: {
+                    // add an additional byte for the contained data type
+                    return helper::readInt32(data, dataSize, currentPosition+prefixSize+1);
                 }
                 case TagType::INT32_ARRAY: {
                     return helper::readInt32(data, dataSize, currentPosition+prefixSize);
diff --git a/src/lib/nbt.hpp b/src/lib/nbt.hpp
index c7174d8..3da58c9 100644
--- a/src/lib/nbt.hpp
+++ b/src/lib/nbt.hpp
@@ -67,8 +67,8 @@ namespace NBT {
         void writeInt64Array(std::vector<uint8_t>* destination, std::vector<int64_t> data);
         void writeInt64Array(std::vector<uint8_t>* destination, int64_t data[], uint32_t dataSize);
 
-        ErrorOr<uint64_t> nextTagTotalSize(uint8_t data[], uint64_t dataSize, uint64_t currentPosition);
-        ErrorOr<int32_t> nextTagDataLength(uint8_t data[], uint64_t dataSize, uint64_t currentPosition);
+        ErrorOr<uint64_t> totalTagSize(uint8_t data[], uint64_t dataSize, uint64_t currentPosition);
+        ErrorOr<int32_t> containedDataLength(uint8_t data[], uint64_t dataSize, uint64_t currentPosition);
     }
 
     namespace TagType {
diff --git a/src/test/nbt_size_helpers.cpp b/src/test/nbt_size_helpers.cpp
index 01a8fea..94c6f73 100644
--- a/src/test/nbt_size_helpers.cpp
+++ b/src/test/nbt_size_helpers.cpp
@@ -37,8 +37,8 @@ int main() {
       0x33, 0x30, 0x30, 0x6e, 0x75, 0x6f, 0x70, 0x09,
       0x00, 0x03
     };
-    ErrorOr<uint64_t> totalSize = NBT::helper::nextTagTotalSize(endTestData, 34, 0);
-    ErrorOr<int32_t> dataLength = NBT::helper::nextTagDataLength(endTestData, 34, 0);
+    ErrorOr<uint64_t> totalSize = NBT::helper::totalTagSize(endTestData, 34, 0);
+    ErrorOr<int32_t> dataLength = NBT::helper::containedDataLength(endTestData, 34, 0);
 
     ASSERT(!totalSize.isError);
     ASSERT(totalSize.value == 1);