diff --git a/halotools/mock_observables/counts_in_cells/engines/counts_in_cylinders_engine.pyx b/halotools/mock_observables/counts_in_cells/engines/counts_in_cylinders_engine.pyx
index d2af4a180..0ab80bf2a 100644
--- a/halotools/mock_observables/counts_in_cells/engines/counts_in_cylinders_engine.pyx
+++ b/halotools/mock_observables/counts_in_cells/engines/counts_in_cylinders_engine.pyx
@@ -146,8 +146,8 @@ def counts_in_cylinders_engine(
 
     cdef bint c_return_indexes = return_indexes
     cdef cnp.int64_t[:] counts = np.zeros(len(x1_sorted), dtype=np.int64)
-    cdef int current_indexes_cnt = 0
-    cdef int current_indexes_len = len(x1_sorted) if c_return_indexes else 0
+    cdef cnp.int64_t current_indexes_cnt = 0
+    cdef cnp.int64_t current_indexes_len = len(x1_sorted) if c_return_indexes else 0
     cdef cnp.uint32_t[:,:] indexes = np.ascontiguousarray(
             np.zeros((current_indexes_len, 2), dtype=np.uint32))