diff --git a/src/gpgmm/common/MemoryAllocator.h b/src/gpgmm/common/MemoryAllocator.h
index 1f856ebda..660176b39 100644
--- a/src/gpgmm/common/MemoryAllocator.h
+++ b/src/gpgmm/common/MemoryAllocator.h
@@ -221,14 +221,14 @@ namespace gpgmm {
 
         /** \brief Return free memory back to the OS.
 
-        @param bytesToRelease Amount of memory to release, in bytes. A kInvalidSize means ALL memory
-        will be released.
+        @param bytesToRelease Amount of memory to release, in bytes. A value of UINT64_MAX
+        releases ALL memory held by the allocator.
 
         \return Amount of memory, in bytes, released. The released size might be smaller then
         bytesToRelease if there was not enough memory or larger if releasable memory doesn't exactly
         total up to the amount.
         */
-        virtual uint64_t ReleaseMemory(uint64_t bytesToRelease = kInvalidSize);
+        virtual uint64_t ReleaseMemory(uint64_t bytesToRelease);
 
         /** \brief Get the fixed-memory sized of the MemoryAllocator.
 
diff --git a/src/gpgmm/d3d12/ResourceAllocatorD3D12.h b/src/gpgmm/d3d12/ResourceAllocatorD3D12.h
index 5aee51d09..f273e323a 100644
--- a/src/gpgmm/d3d12/ResourceAllocatorD3D12.h
+++ b/src/gpgmm/d3d12/ResourceAllocatorD3D12.h
@@ -485,14 +485,14 @@ namespace gpgmm::d3d12 {
         system. Apps should call ReleaseMemory() when going idle for a period of time since there is
         a brief performance hit when the internal resource heaps get reallocated by the OS.
 
-        @param bytesToRelease Amount of memory to release, in bytes. A kInvalidSize means ALL memory
-        will be released.
+        @param bytesToRelease Amount of memory to release, in bytes. A value of UINT64_MAX
+        releases ALL memory held by the allocator.
 
         \return Amount of memory, in bytes, released. The released size might be smaller then
         bytesToRelease if there was not enough memory or larger if releasable memory doesn't exactly
         total up to the amount.
         */
-        uint64_t ReleaseMemory(uint64_t bytesToRelease = kInvalidSize) override;
+        uint64_t ReleaseMemory(uint64_t bytesToRelease) override;
 
         /** \brief  Return the current allocator usage.
 
diff --git a/src/tests/end2end/D3D12ResourceAllocatorTests.cpp b/src/tests/end2end/D3D12ResourceAllocatorTests.cpp
index 061b9c82b..59df80075 100644
--- a/src/tests/end2end/D3D12ResourceAllocatorTests.cpp
+++ b/src/tests/end2end/D3D12ResourceAllocatorTests.cpp
@@ -27,6 +27,7 @@
 using namespace gpgmm::d3d12;
 
 static constexpr uint64_t kDefaultBufferSize = 4ll * 1024ll * 1024ll;  // 4MB
+static constexpr uint64_t kReleaseAllMemory = std::numeric_limits<uint64_t>::max();
 
 #define GPGMM_GET_VAR_NAME(x) (#x)
 
@@ -942,7 +943,7 @@ TEST_F(D3D12ResourceAllocatorTests, CreateBufferPooled) {
 
     EXPECT_EQ(poolAllocator->GetInfo().FreeMemoryUsage, bufferSize + bufferSize / 2);
 
-    EXPECT_EQ(poolAllocator->ReleaseMemory(), bufferSize + bufferSize / 2);
+    EXPECT_EQ(poolAllocator->ReleaseMemory(kReleaseAllMemory), bufferSize + bufferSize / 2);
 
     EXPECT_EQ(poolAllocator->GetInfo().FreeMemoryUsage, 0u);
 
diff --git a/src/tests/unittests/BuddyMemoryAllocatorTests.cpp b/src/tests/unittests/BuddyMemoryAllocatorTests.cpp
index 44cc19888..97a7dabed 100644
--- a/src/tests/unittests/BuddyMemoryAllocatorTests.cpp
+++ b/src/tests/unittests/BuddyMemoryAllocatorTests.cpp
@@ -27,6 +27,7 @@ using namespace gpgmm;
 
 static constexpr uint64_t kDefaultMemorySize = 128u;
 static constexpr uint64_t kDefaultMemoryAlignment = 128u;
+static constexpr uint64_t kReleaseAllMemory = std::numeric_limits<uint64_t>::max();
 
 class BuddyMemoryAllocatorTests : public testing::Test {
   public:
@@ -510,7 +511,7 @@ TEST_F(BuddyMemoryAllocatorTests, ReuseFreedHeaps) {
 
     EXPECT_EQ(allocator.GetInfo().UsedMemoryCount, 0u);
 
-    allocator.ReleaseMemory();
+    allocator.ReleaseMemory(kReleaseAllMemory);
 }
 
 // Verify resource heaps that were reused from a pool can be destroyed.
@@ -550,5 +551,5 @@ TEST_F(BuddyMemoryAllocatorTests, DestroyHeaps) {
 
     EXPECT_EQ(allocator.GetInfo().FreeMemoryUsage, kNumOfHeaps * kDefaultMemorySize);
 
-    allocator.ReleaseMemory();
+    allocator.ReleaseMemory(kReleaseAllMemory);
 }
diff --git a/src/tests/unittests/MemoryAllocatorTests.cpp b/src/tests/unittests/MemoryAllocatorTests.cpp
index edaddd32c..7bf7ca76c 100644
--- a/src/tests/unittests/MemoryAllocatorTests.cpp
+++ b/src/tests/unittests/MemoryAllocatorTests.cpp
@@ -21,6 +21,8 @@
 
 using namespace gpgmm;
 
+static constexpr uint64_t kReleaseAllMemory = std::numeric_limits<uint64_t>::max();
+
 static uint64_t DestructCount = 0;
 static uint64_t ReleaseMemoryCount = 0;
 
@@ -36,7 +38,7 @@ class TestMemoryAllocator final : public DummyMemoryAllocator {
         DestructCount++;
     }
 
-    uint64_t ReleaseMemory(uint64_t bytesToRelease = kInvalidSize) override {
+    uint64_t ReleaseMemory(uint64_t bytesToRelease) override {
         ReleaseMemoryCount++;
         return MemoryAllocator::ReleaseMemory(bytesToRelease);
     }
@@ -56,7 +58,7 @@ TEST_F(MemoryAllocatorTests, SingleAllocator) {
 
     EXPECT_TRUE(parent->GetNextInChain() != nullptr);
 
-    parent->ReleaseMemory();
+    parent->ReleaseMemory(kReleaseAllMemory);
     EXPECT_EQ(ReleaseMemoryCount, 2u);
 
     parent.reset();
@@ -70,7 +72,7 @@ TEST_F(MemoryAllocatorTests, MultipleAllocators) {
 
     EXPECT_TRUE(parent->GetNextInChain() != nullptr);
 
-    parent->ReleaseMemory();
+    parent->ReleaseMemory(kReleaseAllMemory);
     EXPECT_EQ(ReleaseMemoryCount, 3u);
 
     parent.reset();