diff --git a/Tests/UnitTests/TestHelpers/SnapshotTesting+Extensions.swift b/Tests/UnitTests/TestHelpers/SnapshotTesting+Extensions.swift
index 6443e10c97..f84dcb715f 100644
--- a/Tests/UnitTests/TestHelpers/SnapshotTesting+Extensions.swift
+++ b/Tests/UnitTests/TestHelpers/SnapshotTesting+Extensions.swift
@@ -163,8 +163,15 @@ private let pollInterval: DispatchTimeInterval = .milliseconds(100)
 private extension Encodable {
 
     func asFormattedString(backwardsCompatible: Bool) throws -> String {
-        return String(decoding: try self.asFormattedData(backwardsCompatible: backwardsCompatible),
-                      as: UTF8.self)
+        let data = try self.asFormattedData(backwardsCompatible: backwardsCompatible)
+        guard let string = String(data: data, encoding: .utf8) else {
+            throw NSError(
+                domain: "EncodingError",
+                code: 0,
+                userInfo: [NSLocalizedDescriptionKey: "Provided data is not a valid UTF-8 string."]
+            )
+        }
+        return string
     }
 
     func asFormattedData(backwardsCompatible: Bool) throws -> Data {