diff --git a/bson/bsoncodec/uint_codec.go b/bson/bsoncodec/uint_codec.go
index 022a880cbec..7a2f48cbf89 100644
--- a/bson/bsoncodec/uint_codec.go
+++ b/bson/bsoncodec/uint_codec.go
@@ -168,7 +168,7 @@ func (uic *UIntCodec) decodeType(dc DecodeContext, vr bsonrw.ValueReader, t refl
 			return emptyValue, fmt.Errorf("%d overflows uint", i64)
 		}
 
-		return reflect.ValueOf(uint(i64)), nil
+		return reflect.ValueOf(uint(uint64(i64))), nil
 	default:
 		return emptyValue, ValueDecoderError{
 			Name:     "UintDecodeValue",
diff --git a/etc/run-atlas-test.sh b/etc/run-atlas-test.sh
index b1048929739..ae240f6cbf9 100644
--- a/etc/run-atlas-test.sh
+++ b/etc/run-atlas-test.sh
@@ -8,4 +8,4 @@ set +x
 . ${DRIVERS_TOOLS}/.evergreen/secrets_handling/setup-secrets.sh drivers/atlas_connect
 
 echo "Running cmd/testatlas"
-go test -run ^TestAtlas$ go.mongodb.org/mongo-driver/cmd/testatlas -args "$ATLAS_REPL" "$ATLAS_SHRD" "$ATLAS_FREE" "$ATLAS_TLS11" "$ATLAS_TLS12" "$ATLAS_SERVERLESS" "$ATLAS_SRV_REPL" "$ATLAS_SRV_SHRD" "$ATLAS_SRV_FREE" "$ATLAS_SRV_TLS11" "$ATLAS_SRV_TLS12" "$ATLAS_SRV_SERVERLESS" >> test.suite
+go test -v -run ^TestAtlas$ go.mongodb.org/mongo-driver/cmd/testatlas -args "$ATLAS_REPL" "$ATLAS_SHRD" "$ATLAS_FREE" "$ATLAS_TLS11" "$ATLAS_TLS12" "$ATLAS_SERVERLESS" "$ATLAS_SRV_REPL" "$ATLAS_SRV_SHRD" "$ATLAS_SRV_FREE" "$ATLAS_SRV_TLS11" "$ATLAS_SRV_TLS12" "$ATLAS_SRV_SERVERLESS" >> test.suite
diff --git a/x/bsonx/bsoncore/bsoncore.go b/x/bsonx/bsoncore/bsoncore.go
index ead929771ad..03925d7ada1 100644
--- a/x/bsonx/bsoncore/bsoncore.go
+++ b/x/bsonx/bsoncore/bsoncore.go
@@ -707,17 +707,16 @@ func ReserveLength(dst []byte) (int32, []byte) {
 
 // UpdateLength updates the length at index with length and returns the []byte.
 func UpdateLength(dst []byte, index, length int32) []byte {
-	dst[index] = byte(length)
-	dst[index+1] = byte(length >> 8)
-	dst[index+2] = byte(length >> 16)
-	dst[index+3] = byte(length >> 24)
+	binary.LittleEndian.PutUint32(dst[index:], uint32(length))
 	return dst
 }
 
 func appendLength(dst []byte, l int32) []byte { return appendi32(dst, l) }
 
 func appendi32(dst []byte, i32 int32) []byte {
-	return append(dst, byte(i32), byte(i32>>8), byte(i32>>16), byte(i32>>24))
+	b := []byte{0, 0, 0, 0}
+	binary.LittleEndian.PutUint32(b, uint32(i32))
+	return append(dst, b...)
 }
 
 // ReadLength reads an int32 length from src and returns the length and the remaining bytes. If