diff --git a/internal/api/lib_test.go b/internal/api/lib_test.go
index b4bff8da4..3ac275512 100644
--- a/internal/api/lib_test.go
+++ b/internal/api/lib_test.go
@@ -197,12 +197,11 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 3
 	metrics, err = GetMetrics(cache)
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsFsCache:         1,
-		ElementsMemoryCache: 1,
-		SizeMemoryCache:     5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(0), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Instantiate 2
 	msg2 := []byte(`{"verifier": "fred", "beneficiary": "susi"}`)
@@ -211,13 +210,11 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 4
 	metrics, err = GetMetrics(cache)
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsMemoryCache:     1,
-		HitsFsCache:         1,
-		ElementsMemoryCache: 1,
-		SizeMemoryCache:     5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(1), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Pin
 	err = Pin(cache, checksum)
@@ -225,15 +222,13 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 5
 	metrics, err = GetMetrics(cache)
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsMemoryCache:           2,
-		HitsFsCache:               1,
-		ElementsPinnedMemoryCache: 1,
-		ElementsMemoryCache:       1,
-		SizePinnedMemoryCache:     5602873,
-		SizeMemoryCache:           5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(2), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(1), metrics.ElementsPinnedMemoryCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizePinnedMemoryCache, 0.18)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Instantiate 3
 	msg3 := []byte(`{"verifier": "fred", "beneficiary": "bert"}`)
@@ -242,16 +237,14 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 6
 	metrics, err = GetMetrics(cache)
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsPinnedMemoryCache:     1,
-		HitsMemoryCache:           2,
-		HitsFsCache:               1,
-		ElementsPinnedMemoryCache: 1,
-		ElementsMemoryCache:       1,
-		SizePinnedMemoryCache:     5602873,
-		SizeMemoryCache:           5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(1), metrics.HitsPinnedMemoryCache)
+	require.Equal(t, uint32(2), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(1), metrics.ElementsPinnedMemoryCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizePinnedMemoryCache, 0.18)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Unpin
 	err = Unpin(cache, checksum)
@@ -259,16 +252,14 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 7
 	metrics, err = GetMetrics(cache)
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsPinnedMemoryCache:     1,
-		HitsMemoryCache:           2,
-		HitsFsCache:               1,
-		ElementsPinnedMemoryCache: 0,
-		ElementsMemoryCache:       1,
-		SizePinnedMemoryCache:     0,
-		SizeMemoryCache:           5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(1), metrics.HitsPinnedMemoryCache)
+	require.Equal(t, uint32(2), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(0), metrics.ElementsPinnedMemoryCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.Equal(t, uint64(0), metrics.SizePinnedMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Instantiate 4
 	msg4 := []byte(`{"verifier": "fred", "beneficiary": "jeff"}`)
@@ -277,16 +268,14 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 8
 	metrics, err = GetMetrics(cache)
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsPinnedMemoryCache:     1,
-		HitsMemoryCache:           3,
-		HitsFsCache:               1,
-		ElementsPinnedMemoryCache: 0,
-		ElementsMemoryCache:       1,
-		SizePinnedMemoryCache:     0,
-		SizeMemoryCache:           5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(1), metrics.HitsPinnedMemoryCache)
+	require.Equal(t, uint32(3), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(0), metrics.ElementsPinnedMemoryCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.Equal(t, uint64(0), metrics.SizePinnedMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 }
 
 func TestInstantiate(t *testing.T) {
diff --git a/lib_test.go b/lib_test.go
index 0406b6547..b6c087b77 100644
--- a/lib_test.go
+++ b/lib_test.go
@@ -194,12 +194,11 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 3
 	metrics, err = vm.GetMetrics()
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsFsCache:         1,
-		ElementsMemoryCache: 1,
-		SizeMemoryCache:     5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(0), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Instantiate 2
 	msg2 := []byte(`{"verifier": "fred", "beneficiary": "susi"}`)
@@ -209,13 +208,11 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 4
 	metrics, err = vm.GetMetrics()
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsMemoryCache:     1,
-		HitsFsCache:         1,
-		ElementsMemoryCache: 1,
-		SizeMemoryCache:     5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(1), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Pin
 	err = vm.Pin(checksum)
@@ -223,15 +220,13 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 5
 	metrics, err = vm.GetMetrics()
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsMemoryCache:           2,
-		HitsFsCache:               1,
-		ElementsPinnedMemoryCache: 1,
-		ElementsMemoryCache:       1,
-		SizePinnedMemoryCache:     5602873,
-		SizeMemoryCache:           5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(2), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(1), metrics.ElementsPinnedMemoryCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizePinnedMemoryCache, 0.18)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Instantiate 3
 	msg3 := []byte(`{"verifier": "fred", "beneficiary": "bert"}`)
@@ -241,16 +236,14 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 6
 	metrics, err = vm.GetMetrics()
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsPinnedMemoryCache:     1,
-		HitsMemoryCache:           2,
-		HitsFsCache:               1,
-		ElementsPinnedMemoryCache: 1,
-		ElementsMemoryCache:       1,
-		SizePinnedMemoryCache:     5602873,
-		SizeMemoryCache:           5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(1), metrics.HitsPinnedMemoryCache)
+	require.Equal(t, uint32(2), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(1), metrics.ElementsPinnedMemoryCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizePinnedMemoryCache, 0.18)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Unpin
 	err = vm.Unpin(checksum)
@@ -258,16 +251,14 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 7
 	metrics, err = vm.GetMetrics()
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsPinnedMemoryCache:     1,
-		HitsMemoryCache:           2,
-		HitsFsCache:               1,
-		ElementsPinnedMemoryCache: 0,
-		ElementsMemoryCache:       1,
-		SizePinnedMemoryCache:     0,
-		SizeMemoryCache:           5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(1), metrics.HitsPinnedMemoryCache)
+	require.Equal(t, uint32(2), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(0), metrics.ElementsPinnedMemoryCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.Equal(t, uint64(0), metrics.SizePinnedMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 
 	// Instantiate 4
 	msg4 := []byte(`{"verifier": "fred", "beneficiary": "jeff"}`)
@@ -277,14 +268,12 @@ func TestGetMetrics(t *testing.T) {
 
 	// GetMetrics 8
 	metrics, err = vm.GetMetrics()
-	require.NoError(t, err)
-	assert.Equal(t, &types.Metrics{
-		HitsPinnedMemoryCache:     1,
-		HitsMemoryCache:           3,
-		HitsFsCache:               1,
-		ElementsPinnedMemoryCache: 0,
-		ElementsMemoryCache:       1,
-		SizePinnedMemoryCache:     0,
-		SizeMemoryCache:           5602873,
-	}, metrics)
+	assert.NoError(t, err)
+	require.Equal(t, uint32(1), metrics.HitsPinnedMemoryCache)
+	require.Equal(t, uint32(3), metrics.HitsMemoryCache)
+	require.Equal(t, uint32(1), metrics.HitsFsCache)
+	require.Equal(t, uint64(0), metrics.ElementsPinnedMemoryCache)
+	require.Equal(t, uint64(1), metrics.ElementsMemoryCache)
+	require.Equal(t, uint64(0), metrics.SizePinnedMemoryCache)
+	require.InEpsilon(t, 5602873, metrics.SizeMemoryCache, 0.18)
 }
diff --git a/libwasmvm/Cargo.toml b/libwasmvm/Cargo.toml
index 1768ecbf4..ce99a94df 100644
--- a/libwasmvm/Cargo.toml
+++ b/libwasmvm/Cargo.toml
@@ -3,7 +3,7 @@ name = "wasmvm"
 version = "1.0.0"
 publish = false
 authors = ["Ethan Frey <ethanfrey@users.noreply.github.com>"]
-edition = "2018"
+edition = "2021"
 description = "Go bindings for cosmwasm contracts"
 repository = "https://github.com/CosmWasm/wasmvm"
 license = "Apache-2.0"
diff --git a/libwasmvm/src/cache.rs b/libwasmvm/src/cache.rs
index 2ac190474..e94b4bd3a 100644
--- a/libwasmvm/src/cache.rs
+++ b/libwasmvm/src/cache.rs
@@ -695,19 +695,32 @@ mod tests {
         let mut error_msg = UnmanagedVector::default();
         let metrics = get_metrics(cache_ptr, Some(&mut error_msg));
         let _ = error_msg.consume();
-        assert_eq!(
-            metrics,
-            Metrics {
-                hits_pinned_memory_cache: 0,
-                hits_memory_cache: 0,
-                hits_fs_cache: 1,
-                misses: 0,
-                elements_pinned_memory_cache: 1,
-                elements_memory_cache: 0,
-                size_pinned_memory_cache: 5602873,
-                size_memory_cache: 0,
-            }
+        let Metrics {
+            hits_pinned_memory_cache,
+            hits_memory_cache,
+            hits_fs_cache,
+            misses,
+            elements_pinned_memory_cache,
+            elements_memory_cache,
+            size_pinned_memory_cache,
+            size_memory_cache,
+        } = metrics;
+        assert_eq!(hits_pinned_memory_cache, 0);
+        assert_eq!(hits_memory_cache, 0);
+        assert_eq!(hits_fs_cache, 1);
+        assert_eq!(misses, 0);
+        assert_eq!(elements_pinned_memory_cache, 1);
+        assert_eq!(elements_memory_cache, 0);
+        let expected = 5602873; // +/- 20%
+        assert!(
+            size_pinned_memory_cache > expected * 80 / 100,
+            "size_pinned_memory_cache: {size_pinned_memory_cache}"
+        );
+        assert!(
+            size_pinned_memory_cache < expected * 120 / 100,
+            "size_pinned_memory_cache: {size_pinned_memory_cache}"
         );
+        assert_eq!(size_memory_cache, 0);
 
         // Unpin
         let mut error_msg = UnmanagedVector::default();