diff --git a/src/lib/nbt.cpp b/src/lib/nbt.cpp
index 91d2b3b..6a8a329 100644
--- a/src/lib/nbt.cpp
+++ b/src/lib/nbt.cpp
@@ -146,11 +146,16 @@ namespace NBT {
         }
 
         ErrorOr<tiny_utf8::string> readString(uint8_t data[], uint64_t dataSize, uint64_t currentPosition) {
-            if(dataSize > 0xFFFF){
+            if(currentPosition > dataSize){
                 return ErrorOr<tiny_utf8::string>(true, ErrorCodes::OVERRUN);
             }
 
-            ErrorOr<tiny_utf8::string> output = JavaCompat::importJavaString(data+currentPosition, (uint16_t) dataSize);
+            ErrorOr<int16_t> stringSize = readInt16(data, dataSize, currentPosition);
+            if (stringSize.isError) {
+                return ErrorOr<tiny_utf8::string>(true, stringSize.errorCode);
+            }
+
+            ErrorOr<tiny_utf8::string> output = JavaCompat::importJavaString(data+currentPosition, stringSize.value);
             if(output.isError){
                 return ErrorOr<tiny_utf8::string>(true, output.errorCode);
             }