diff --git a/src/main/java/io/github/tap30/hiss/HissEncryptor.java b/src/main/java/io/github/tap30/hiss/HissEncryptor.java
index 2aa8ef7..5739b43 100644
--- a/src/main/java/io/github/tap30/hiss/HissEncryptor.java
+++ b/src/main/java/io/github/tap30/hiss/HissEncryptor.java
@@ -6,11 +6,14 @@
 import org.intellij.lang.annotations.Language;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Objects;
+
 class HissEncryptor {
 
     private final HissProperties hissProperties;
 
     public HissEncryptor(HissProperties hissProperties) {
+        Objects.requireNonNull(hissProperties);
         this.hissProperties = hissProperties;
     }
 
diff --git a/src/main/java/io/github/tap30/hiss/properties/HissPropertiesFromEnv.java b/src/main/java/io/github/tap30/hiss/properties/HissPropertiesFromEnv.java
index c7e013f..bc4706b 100644
--- a/src/main/java/io/github/tap30/hiss/properties/HissPropertiesFromEnv.java
+++ b/src/main/java/io/github/tap30/hiss/properties/HissPropertiesFromEnv.java
@@ -8,6 +8,7 @@
 import java.util.Set;
 import java.util.function.Supplier;
 
+// Todo: import doc
 /**
  * Sample Envs:
  * <br>
diff --git a/src/main/java/io/github/tap30/hiss/properties/HissPropertiesValidator.java b/src/main/java/io/github/tap30/hiss/properties/HissPropertiesValidator.java
index a428a29..89715b3 100644
--- a/src/main/java/io/github/tap30/hiss/properties/HissPropertiesValidator.java
+++ b/src/main/java/io/github/tap30/hiss/properties/HissPropertiesValidator.java
@@ -9,10 +9,10 @@
 
 public class HissPropertiesValidator {
 
-    private static final Set<String> SUPPORTED_ENCRYPTION_ALGORITHMS
-            = Set.of("aes-128-gcm", "aes-128-cbc"); // Todo: get these from algorithm spec
-    private static final Set<String> SUPPORTED_HASHING_ALGORITHMS
-            = Set.of("hmac-sha256"); // Todo: get this from algorithm spec
+    private static final Set<String> SUPPORTED_ENCRYPTION_ALGORITHMS =
+            Set.of("aes-128-gcm", "aes-128-cbc"); // Todo: get these from algorithm spec
+    private static final Set<String> SUPPORTED_HASHING_ALGORITHMS =
+            Set.of("hmac-sha256"); // Todo: get this from algorithm spec
 
     private final KeyHashGenerator keyHashGenerator;