diff --git a/util/env_posix.cc b/util/env_posix.cc
index 86571059b..c0cca69a9 100644
--- a/util/env_posix.cc
+++ b/util/env_posix.cc
@@ -42,8 +42,8 @@ namespace {
 // Set by EnvPosixTestHelper::SetReadOnlyMMapLimit() and MaxOpenFiles().
 int g_open_read_only_file_limit = -1;
 
-// Up to 4096 mmap regions for 64-bit binaries; none for 32-bit.
-constexpr const int kDefaultMmapLimit = (sizeof(void*) >= 8) ? 4096 : 0;
+// Up to 1000 mmap regions for 64-bit binaries; none for 32-bit.
+constexpr const int kDefaultMmapLimit = (sizeof(void*) >= 8) ? 1000 : 0;
 
 // Can be set using EnvPosixTestHelper::SetReadOnlyMMapLimit().
 int g_mmap_limit = kDefaultMmapLimit;