diff --git a/pysheds/grid.py b/pysheds/grid.py
index 390c86f..cf98a0f 100644
--- a/pysheds/grid.py
+++ b/pysheds/grid.py
@@ -1255,7 +1255,7 @@ def _d8_accumulation(self, fdir=None, weights=None, dirmap=None, nodata_in=None,
             invalid_entries = fdir.flat[invalid_cells]
             fdir.flat[invalid_cells] = 0
             # Ensure consistent types
-            fdir = fdir.astype(mintype)
+            fdir = fdir.astype('int32')
             # Set nodata cells to zero
             fdir[nodata_cells] = 0
             # Get matching of start and end nodes