diff --git a/libs/protoutil/src/EncodedBuffer.cpp b/libs/protoutil/src/EncodedBuffer.cpp
index 96b54c6..afb54a6 100644
--- a/libs/protoutil/src/EncodedBuffer.cpp
+++ b/libs/protoutil/src/EncodedBuffer.cpp
@@ -17,6 +17,7 @@
 
 #include <stdlib.h>
 #include <sys/mman.h>
+#include <unistd.h>
 
 #include <android/util/EncodedBuffer.h>
 #include <android/util/protobuf.h>
@@ -25,7 +26,8 @@
 namespace android {
 namespace util {
 
-const size_t BUFFER_SIZE = 8 * 1024; // 8 KB
+constexpr size_t BUFFER_SIZE = 8 * 1024; // 8 KB
+const size_t kPageSize = getpagesize();
 
 EncodedBuffer::Pointer::Pointer() : Pointer(BUFFER_SIZE)
 {
@@ -92,7 +94,7 @@
 {
     // Align chunkSize to memory page size
     chunkSize = chunkSize == 0 ? BUFFER_SIZE : chunkSize;
-    mChunkSize = (chunkSize / PAGE_SIZE + ((chunkSize % PAGE_SIZE == 0) ? 0 : 1)) * PAGE_SIZE;
+    mChunkSize = (chunkSize + (kPageSize - 1)) & ~(kPageSize - 1);
     mWp = Pointer(mChunkSize);
     mEp = Pointer(mChunkSize);
 }
diff --git a/libs/protoutil/tests/EncodedBuffer_test.cpp b/libs/protoutil/tests/EncodedBuffer_test.cpp
index 8a7becf..a0955854 100644
--- a/libs/protoutil/tests/EncodedBuffer_test.cpp
+++ b/libs/protoutil/tests/EncodedBuffer_test.cpp
@@ -15,13 +15,16 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
+#include <unistd.h>
+
 using namespace android::util;
 using android::sp;
 
 constexpr size_t __TEST_CHUNK_SIZE = 16UL;
-constexpr size_t TEST_CHUNK_SIZE = (__TEST_CHUNK_SIZE + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
-constexpr size_t TEST_CHUNK_HALF_SIZE = TEST_CHUNK_SIZE / 2;
-constexpr size_t TEST_CHUNK_3X_SIZE = 3 * TEST_CHUNK_SIZE;
+const size_t kPageSize = getpagesize();
+const size_t TEST_CHUNK_SIZE = (__TEST_CHUNK_SIZE + (kPageSize - 1)) & ~(kPageSize - 1);
+const size_t TEST_CHUNK_HALF_SIZE = TEST_CHUNK_SIZE / 2;
+const size_t TEST_CHUNK_3X_SIZE = 3 * TEST_CHUNK_SIZE;
 
 static void expectPointer(EncodedBuffer::Pointer* p, size_t pos) {
     EXPECT_EQ(p->pos(), pos);