diff --git a/code/Common/ZipArchiveIOSystem.cpp b/code/Common/ZipArchiveIOSystem.cpp
index 463c2071b..43c66a921 100644
--- a/code/Common/ZipArchiveIOSystem.cpp
+++ b/code/Common/ZipArchiveIOSystem.cpp
@@ -45,7 +45,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <assimp/ai_assert.h>
 
-#include <unordered_map>
+#include <map>
 #include <memory>
 
 #ifdef ASSIMP_USE_HUNTER
@@ -55,7 +55,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 namespace Assimp {
-
     // ----------------------------------------------------------------
     // Wraps an existing Assimp::IOSystem for unzip
     class IOSystem2Unzip {
@@ -247,14 +246,25 @@ namespace Assimp {
     }
 
     size_t ZipFile::Read(void* pvBuffer, size_t pSize, size_t pCount) {
-        const size_t size = pSize * pCount;
-        ai_assert((size + m_SeekPtr) <= m_Size);
+        // Should be impossible
+        ai_assert(m_Buffer != nullptr);
+        ai_assert(NULL != pvBuffer && 0 != pSize && 0 != pCount);
 
-        std::memcpy(pvBuffer, m_Buffer.get() + m_SeekPtr, size);
+        // Clip down to file size
+        size_t byteSize = pSize * pCount;
+        if ((byteSize + m_SeekPtr) > m_Size)
+        {
+            pCount = (m_Size - m_SeekPtr) / pSize;
+            byteSize = pSize * pCount;
+            if (byteSize == 0)
+                return 0;
+        }
 
-        m_SeekPtr += size;
+        std::memcpy(pvBuffer, m_Buffer.get() + m_SeekPtr, byteSize);
 
-        return size;
+        m_SeekPtr += byteSize;
+
+        return pCount;
     }
 
     size_t ZipFile::FileSize() const {
@@ -312,9 +322,10 @@ namespace Assimp {
         void MapArchive();
 
     private:
+        typedef std::map<std::string, ZipFileInfo> ZipFileInfoMap;
+
         unzFile m_ZipFileHandle = nullptr;
-        typedef std::unordered_map<std::string, ZipFileInfo> ZipFileMap;
-        ZipFileMap m_ArchiveMap;
+        ZipFileInfoMap m_ArchiveMap;
     };
 
     ZipArchiveIOSystem::Implement::Implement(IOSystem* pIOHandler, const char* pFilename, const char* pMode) {
@@ -388,7 +399,7 @@ namespace Assimp {
     bool ZipArchiveIOSystem::Implement::Exists(std::string& filename) {
         MapArchive();
 
-        ZipFileMap::const_iterator it = m_ArchiveMap.find(filename);
+        ZipFileInfoMap::const_iterator it = m_ArchiveMap.find(filename);
         return (it != m_ArchiveMap.end());
     }
 
@@ -398,7 +409,7 @@ namespace Assimp {
         SimplifyFilename(filename);
 
         // Find in the map
-        ZipFileMap::const_iterator zip_it = m_ArchiveMap.find(filename);
+        ZipFileInfoMap::const_iterator zip_it = m_ArchiveMap.find(filename);
         if (zip_it == m_ArchiveMap.cend())
             return nullptr;