diff --git a/include/pocketpy/cffi.h b/include/pocketpy/cffi.h
index ed4ad476..9fafb79f 100644
--- a/include/pocketpy/cffi.h
+++ b/include/pocketpy/cffi.h
@@ -34,7 +34,6 @@ struct VoidP{
 
     void* ptr;
     VoidP(const void* ptr): ptr(const_cast<void*>(ptr)){}
-    VoidP(void* ptr): ptr(ptr){}
 
     bool operator==(const VoidP& other) const {
         return ptr == other.ptr;