diff --git a/common/datastore/CDataStore.cpp b/common/datastore/CDataStore.cpp
index b67e1a7..aef6a28 100644
--- a/common/datastore/CDataStore.cpp
+++ b/common/datastore/CDataStore.cpp
@@ -270,3 +270,7 @@ CDataStore& CDataStore::Set(uint32_t pos, uint16_t val) {
 
     return *this;
 }
+
+bool CDataStore::Sub8CBBF0(uint32_t a2) {
+    return this->m_read <= this->m_size && this->m_size - this->m_read >= a2;
+}
diff --git a/common/datastore/CDataStore.hpp b/common/datastore/CDataStore.hpp
index 727e5eb..d13dd6c 100644
--- a/common/datastore/CDataStore.hpp
+++ b/common/datastore/CDataStore.hpp
@@ -41,6 +41,7 @@ class CDataStore {
     CDataStore& PutArray(const uint8_t* val, uint32_t count);
     CDataStore& PutData(const void* val, uint32_t bytes);
     CDataStore& Set(uint32_t pos, uint16_t val);
+    bool Sub8CBBF0(uint32_t a2);
 };
 
 #endif