diff --git a/app/src/main/java/eu/faircode/email/ApplicationEx.java b/app/src/main/java/eu/faircode/email/ApplicationEx.java
index 3f7b57b4d6..5ab86b0b9f 100644
--- a/app/src/main/java/eu/faircode/email/ApplicationEx.java
+++ b/app/src/main/java/eu/faircode/email/ApplicationEx.java
@@ -516,6 +516,9 @@ public class ApplicationEx extends Application
                 if (!prefs.contains("landscape3"))
                     editor.putBoolean("landscape3", false);
             }
+        } else if (version < 17150) {
+            editor.remove("sign_algo_smime");
+            editor.remove("encrypt_algo_smime");
         }
 
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && !BuildConfig.DEBUG)
diff --git a/app/src/main/java/eu/faircode/email/FragmentCompose.java b/app/src/main/java/eu/faircode/email/FragmentCompose.java
index 7086f6b0c1..5854b7e05f 100644
--- a/app/src/main/java/eu/faircode/email/FragmentCompose.java
+++ b/app/src/main/java/eu/faircode/email/FragmentCompose.java
@@ -3434,12 +3434,7 @@ public class FragmentCompose extends FragmentBase {
                 CMSSignedDataGenerator cmsGenerator = new CMSSignedDataGenerator();
                 cmsGenerator.addCertificates(store);
 
-                String signAlgorithm = prefs.getString("sign_algo_smime", "SHA256");
-
-                // https://datatracker.ietf.org/doc/html/rfc5751#page-29
-                String micalg = signAlgorithm.toLowerCase(Locale.ROOT);
-                if (micalg.startsWith("sha"))
-                    micalg = micalg.substring(0, 3) + "-" + micalg.substring(3);
+                String signAlgorithm = prefs.getString("sign_algo_smime", "SHA-256");
 
                 String algorithm = privkey.getAlgorithm();
                 if (TextUtils.isEmpty(algorithm) || "RSA".equals(algorithm))
@@ -3477,7 +3472,7 @@ public class FragmentCompose extends FragmentBase {
                 // Build signature
                 if (EntityMessage.SMIME_SIGNONLY.equals(type)) {
                     ContentType ct = new ContentType("application/pkcs7-signature");
-                    ct.setParameter("micalg", micalg);
+                    ct.setParameter("micalg", signAlgorithm.toLowerCase(Locale.ROOT));
 
                     EntityAttachment sattachment = new EntityAttachment();
                     sattachment.message = draft.id;
@@ -3550,7 +3545,7 @@ public class FragmentCompose extends FragmentBase {
 
                 // Build message
                 ContentType ct = new ContentType("multipart/signed");
-                ct.setParameter("micalg", micalg);
+                ct.setParameter("micalg", signAlgorithm.toLowerCase(Locale.ROOT));
                 ct.setParameter("protocol", "application/pkcs7-signature");
                 ct.setParameter("smime-type", "signed-data");
                 String ctx = ct.toString();
@@ -3587,17 +3582,16 @@ public class FragmentCompose extends FragmentBase {
                 }
                 CMSTypedData msg = new CMSProcessableFile(einput);
 
-                // https://datatracker.ietf.org/doc/html/rfc5751#section-2.7
                 ASN1ObjectIdentifier encryptionOID;
-                String encryptAlgorithm = prefs.getString("encrypt_algo_smime", "AES128");
+                String encryptAlgorithm = prefs.getString("encrypt_algo_smime", "AES-128");
                 switch (encryptAlgorithm) {
-                    case "AES128":
+                    case "AES-128":
                         encryptionOID = CMSAlgorithm.AES128_CBC;
                         break;
-                    case "AES192":
+                    case "AES-192":
                         encryptionOID = CMSAlgorithm.AES192_CBC;
                         break;
-                    case "AES256":
+                    case "AES-256":
                         encryptionOID = CMSAlgorithm.AES256_CBC;
                         break;
                     default:
diff --git a/app/src/main/java/eu/faircode/email/FragmentOptionsEncryption.java b/app/src/main/java/eu/faircode/email/FragmentOptionsEncryption.java
index 43dcd9eeab..965147c7fe 100644
--- a/app/src/main/java/eu/faircode/email/FragmentOptionsEncryption.java
+++ b/app/src/main/java/eu/faircode/email/FragmentOptionsEncryption.java
@@ -471,7 +471,7 @@ public class FragmentOptionsEncryption extends FragmentBase implements SharedPre
         swAutocryptMutual.setEnabled(swAutocrypt.isChecked());
         swEncryptSubject.setChecked(prefs.getBoolean("encrypt_subject", false));
 
-        String signAlgorithm = prefs.getString("sign_algo_smime", "SHA256");
+        String signAlgorithm = prefs.getString("sign_algo_smime", "SHA-256");
         String[] smimeSignAlgo = getResources().getStringArray(R.array.smimeSignAlgo);
         for (int pos = 0; pos < smimeSignAlgo.length; pos++)
             if (smimeSignAlgo[pos].equals(signAlgorithm)) {
@@ -479,7 +479,7 @@ public class FragmentOptionsEncryption extends FragmentBase implements SharedPre
                 break;
             }
 
-        String encryptAlgorithm = prefs.getString("encrypt_algo_smime", "AES128");
+        String encryptAlgorithm = prefs.getString("encrypt_algo_smime", "AES-128");
         String[] smimeEncryptAlgo = getResources().getStringArray(R.array.smimeEncryptAlgo);
         for (int pos = 0; pos < smimeEncryptAlgo.length; pos++)
             if (smimeEncryptAlgo[pos].equals(encryptAlgorithm)) {
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index b758a4a72a..5bff6ccf41 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -2023,19 +2023,21 @@
     </string-array>
 
     <!-- https://www.bouncycastle.org/specifications.html -->
+    <!-- https://datatracker.ietf.org/doc/html/rfc5751#page-29 -->
     <string-array name="smimeSignAlgo" translatable="false">
         <item>MD5</item>
-        <item>SHA1</item>
-        <item>SHA224</item>
-        <item>SHA256</item>
-        <item>SHA384</item>
-        <item>SHA512</item>
+        <item>SHA-1</item>
+        <item>SHA-224</item>
+        <item>SHA-256</item>
+        <item>SHA-384</item>
+        <item>SHA-512</item>
     </string-array>
 
+    <!-- https://datatracker.ietf.org/doc/html/rfc5751#section-2.7 -->
     <string-array name="smimeEncryptAlgo" translatable="false">
-        <item>AES128</item>
-        <item>AES192</item>
-        <item>AES256</item>
+        <item>AES-128</item>
+        <item>AES-192</item>
+        <item>AES-256</item>
     </string-array>
 
     <string name="fingerprint" translatable="false">17BA15C1AF55D925F98B99CEA4375D4CDF4C174B</string>