diff --git a/pandas/_libs/algos.pyx b/pandas/_libs/algos.pyx
index 29f9a22c9b36e..c05d6a300ccf0 100644
--- a/pandas/_libs/algos.pyx
+++ b/pandas/_libs/algos.pyx
@@ -324,6 +324,7 @@ def kth_smallest(numeric_t[::1] arr, Py_ssize_t k) -> numeric_t:
 
 @cython.boundscheck(False)
 @cython.wraparound(False)
+@cython.cdivision(True)
 def nancorr(const float64_t[:, :] mat, bint cov=False, minp=None):
     cdef:
         Py_ssize_t i, j, xi, yi, N, K
@@ -356,8 +357,8 @@ def nancorr(const float64_t[:, :] mat, bint cov=False, minp=None):
                         nobs += 1
                         dx = vx - meanx
                         dy = vy - meany
-                        meanx += 1 / nobs * dx
-                        meany += 1 / nobs * dy
+                        meanx += 1. / nobs * dx
+                        meany += 1. / nobs * dy
                         ssqdmx += (vx - meanx) * dx
                         ssqdmy += (vy - meany) * dy
                         covxy += (vx - meanx) * dy