diff --git a/sop-java/src/main/java/sop/operation/GenerateKey.java b/sop-java/src/main/java/sop/operation/GenerateKey.java
index 27a3b19..b788785 100644
--- a/sop-java/src/main/java/sop/operation/GenerateKey.java
+++ b/sop-java/src/main/java/sop/operation/GenerateKey.java
@@ -6,6 +6,7 @@ package sop.operation;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.charset.CharacterCodingException;
 
 import sop.Profile;
 import sop.Ready;
@@ -54,7 +55,11 @@ public interface GenerateKey {
     default GenerateKey withKeyPassword(byte[] password)
             throws SOPGPException.PasswordNotHumanReadable,
             SOPGPException.UnsupportedOption {
-        return withKeyPassword(UTF8Util.decodeUTF8(password));
+        try {
+            return withKeyPassword(UTF8Util.decodeUTF8(password));
+        } catch (CharacterCodingException e) {
+            throw new SOPGPException.PasswordNotHumanReadable();
+        }
     }
 
     /**
diff --git a/sop-java/src/main/java/sop/util/UTF8Util.java b/sop-java/src/main/java/sop/util/UTF8Util.java
index ec3c22d..a59ff43 100644
--- a/sop-java/src/main/java/sop/util/UTF8Util.java
+++ b/sop-java/src/main/java/sop/util/UTF8Util.java
@@ -4,8 +4,6 @@
 
 package sop.util;
 
-import sop.exception.SOPGPException;
-
 import java.nio.ByteBuffer;
 import java.nio.CharBuffer;
 import java.nio.charset.CharacterCodingException;
@@ -15,7 +13,8 @@ import java.nio.charset.CodingErrorAction;
 
 public class UTF8Util {
 
-    private static final CharsetDecoder UTF8Decoder = Charset.forName("UTF8")
+    public static final Charset UTF8 = Charset.forName("UTF8");
+    private static final CharsetDecoder UTF8Decoder = UTF8
             .newDecoder()
             .onUnmappableCharacter(CodingErrorAction.REPORT)
             .onMalformedInput(CodingErrorAction.REPORT);
@@ -28,13 +27,10 @@ public class UTF8Util {
      *
      * @return decoded string
      */
-    public static String decodeUTF8(byte[] data) {
+    public static String decodeUTF8(byte[] data)
+            throws CharacterCodingException {
         ByteBuffer byteBuffer = ByteBuffer.wrap(data);
-        try {
-            CharBuffer charBuffer = UTF8Decoder.decode(byteBuffer);
-            return charBuffer.toString();
-        } catch (CharacterCodingException e) {
-            throw new SOPGPException.PasswordNotHumanReadable();
-        }
+        CharBuffer charBuffer = UTF8Decoder.decode(byteBuffer);
+        return charBuffer.toString();
     }
 }
diff --git a/sop-java/src/test/java/sop/util/UTF8UtilTest.java b/sop-java/src/test/java/sop/util/UTF8UtilTest.java
index 775d273..95906bc 100644
--- a/sop-java/src/test/java/sop/util/UTF8UtilTest.java
+++ b/sop-java/src/test/java/sop/util/UTF8UtilTest.java
@@ -5,8 +5,8 @@
 package sop.util;
 
 import org.junit.jupiter.api.Test;
-import sop.exception.SOPGPException;
 
+import java.nio.charset.CharacterCodingException;
 import java.nio.charset.StandardCharsets;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -15,7 +15,7 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 public class UTF8UtilTest {
 
     @Test
-    public void testValidUtf8Decoding() {
+    public void testValidUtf8Decoding() throws CharacterCodingException {
         String utf8String = "Hello, World\n";
         String decoded = UTF8Util.decodeUTF8(utf8String.getBytes(StandardCharsets.UTF_8));
 
@@ -29,11 +29,11 @@ public class UTF8UtilTest {
      */
     @Test
     public void testInvalidUtf8StringThrows() {
-        assertThrows(SOPGPException.PasswordNotHumanReadable.class,
+        assertThrows(CharacterCodingException.class,
                 () -> UTF8Util.decodeUTF8(new byte[] {(byte) 0xa0, (byte) 0xa1}));
-        assertThrows(SOPGPException.PasswordNotHumanReadable.class,
+        assertThrows(CharacterCodingException.class,
                 () -> UTF8Util.decodeUTF8(new byte[] {(byte) 0xc0, (byte) 0xaf}));
-        assertThrows(SOPGPException.PasswordNotHumanReadable.class,
+        assertThrows(CharacterCodingException.class,
                 () -> UTF8Util.decodeUTF8(new byte[] {(byte) 0x80, (byte) 0xbf}));
     }
 }