diff --git a/Tests/large_memory_numpy_test.py b/Tests/large_memory_numpy_test.py
index deb2fc8c6..8a13d0aea 100644
--- a/Tests/large_memory_numpy_test.py
+++ b/Tests/large_memory_numpy_test.py
@@ -1,3 +1,5 @@
+import sys
+
 from helper import *
 
 # This test is not run automatically.
@@ -18,6 +20,7 @@ YDIM = 32769
 XDIM = 48000
 
 
+@unittest.skipIf(sys.maxsize <= 2**32, "requires 64 bit system")
 class LargeMemoryNumpyTest(PillowTestCase):
 
     def _write_png(self, xdim, ydim):
diff --git a/Tests/large_memory_test.py b/Tests/large_memory_test.py
index 8552ed4dd..a63a42cd5 100644
--- a/Tests/large_memory_test.py
+++ b/Tests/large_memory_test.py
@@ -1,3 +1,5 @@
+import sys
+
 from helper import *
 
 # This test is not run automatically.
@@ -14,6 +16,7 @@ YDIM = 32769
 XDIM = 48000
 
 
+@unittest.skipIf(sys.maxsize <= 2**32, "requires 64 bit system")
 class LargeMemoryTest(PillowTestCase):
 
     def _write_png(self, xdim, ydim):