diff --git a/matplotlibcpp.h b/matplotlibcpp.h
index 93a72be..ab615c6 100644
--- a/matplotlibcpp.h
+++ b/matplotlibcpp.h
@@ -337,9 +337,7 @@ template <> struct select_npy_type<uint64_t> { const static NPY_TYPES type = NPY
 // Sanity checks; comment them out or change the numpy type below if you're compiling on
 // a platform where they don't apply
 static_assert(sizeof(long long) == 8);
-template <> struct select_npy_type<long long> { const static NPY_TYPES type = NPY_INT64; };
 static_assert(sizeof(unsigned long long) == 8);
-template <> struct select_npy_type<unsigned long long> { const static NPY_TYPES type = NPY_UINT64; };
 // TODO: add int, long, etc.
 
 template<typename Numeric>