diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/UncachedKeyRing.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/UncachedKeyRing.java
index fe4e7ffa7..d64c3ea55 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/UncachedKeyRing.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/UncachedKeyRing.java
@@ -438,6 +438,10 @@ public class UncachedKeyRing {
                                 badCerts += 1;
                                 continue;
                             }
+                            // warn user if the signature was made with bad encoding
+                            if (!cert.verifySignature(masterKey, userId)) {
+                                log.add(LogLevel.WARN, LogType.MSG_KC_UID_WARN_ENCODING, indent);
+                            }
                         } catch (PgpGeneralException e) {
                             log.add(LogLevel.WARN, LogType.MSG_KC_UID_BAD_ERR,
                                     indent, userId);
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/results/OperationResultParcel.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/results/OperationResultParcel.java
index 1a77d96d3..46823a24d 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/results/OperationResultParcel.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/results/OperationResultParcel.java
@@ -339,6 +339,7 @@ public class OperationResultParcel implements Parcelable {
         MSG_KC_UID_REVOKE_DUP (R.string.msg_kc_uid_revoke_dup),
         MSG_KC_UID_REVOKE_OLD (R.string.msg_kc_uid_revoke_old),
         MSG_KC_UID_REMOVE (R.string.msg_kc_uid_remove),
+        MSG_KC_UID_WARN_ENCODING (R.string.msg_kc_uid_warn_encoding),
 
 
         // keyring consolidation
diff --git a/OpenKeychain/src/main/res/values/strings.xml b/OpenKeychain/src/main/res/values/strings.xml
index 378d68c21..9e9b47c7c 100644
--- a/OpenKeychain/src/main/res/values/strings.xml
+++ b/OpenKeychain/src/main/res/values/strings.xml
@@ -661,6 +661,7 @@
     <string name="msg_kc_uid_no_cert">"No valid self-certificate found for user id '%s', removing from ring"</string>
     <string name="msg_kc_uid_remove">"Removing invalid user id '%s'"</string>
     <string name="msg_kc_uid_dup">"Removing duplicate user id '%s'. The secret key contained two of them. This may result in missing certificates!"</string>
+    <string name="msg_kc_uid_warn_encoding">"User id does not verify as UTF-8!"</string>
 
     <!-- Keyring merging log entries -->
     <string name="msg_mg_error_secret_dummy">"New public subkey found, but secret subkey dummy generation is not supported!"</string>