diff --git a/app/src/main/java/com/zeapo/pwdstore/PasswordGeneratorDialogFragment.java b/app/src/main/java/com/zeapo/pwdstore/PasswordGeneratorDialogFragment.java
index f161b927..698ec495 100644
--- a/app/src/main/java/com/zeapo/pwdstore/PasswordGeneratorDialogFragment.java
+++ b/app/src/main/java/com/zeapo/pwdstore/PasswordGeneratorDialogFragment.java
@@ -13,9 +13,13 @@ import android.widget.Button;
 import android.widget.CheckBox;
 import android.widget.EditText;
 import android.widget.TextView;
+import android.widget.Toast;
+
 import androidx.appcompat.app.AlertDialog;
 import androidx.fragment.app.DialogFragment;
+
 import com.zeapo.pwdstore.pwgen.PasswordGenerator;
+
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
@@ -53,6 +57,9 @@ public class PasswordGeneratorDialogFragment extends DialogFragment {
         checkBox = view.findViewById(R.id.uppercase);
         checkBox.setChecked(!prefs.getBoolean("A", false));
 
+        checkBox = view.findViewById(R.id.lowercase);
+        checkBox.setChecked(!prefs.getBoolean("L", false));
+
         checkBox = view.findViewById(R.id.ambiguous);
         checkBox.setChecked(!prefs.getBoolean("B", false));
 
@@ -79,12 +86,22 @@ public class PasswordGeneratorDialogFragment extends DialogFragment {
         final AlertDialog ad = builder.setTitle(this.getResources().getString(R.string.pwgen_title)).create();
         ad.setOnShowListener(dialog -> {
             setPreferences();
-            passwordText.setText(PasswordGenerator.INSTANCE.generate(getActivity().getApplicationContext()).get(0));
+            try {
+                passwordText.setText(PasswordGenerator.INSTANCE.generate(getActivity().getApplicationContext()).get(0));
+            } catch (PasswordGenerator.PasswordGeneratorExeption e) {
+                Toast.makeText(getActivity(), e.getMessage(), Toast.LENGTH_SHORT).show();
+                passwordText.setText("");
+            }
 
             Button b = ad.getButton(AlertDialog.BUTTON_NEUTRAL);
             b.setOnClickListener(v -> {
                 setPreferences();
-                passwordText.setText(PasswordGenerator.INSTANCE.generate(callingActivity.getApplicationContext()).get(0));
+                try {
+                    passwordText.setText(PasswordGenerator.INSTANCE.generate(callingActivity.getApplicationContext()).get(0));
+                } catch (PasswordGenerator.PasswordGeneratorExeption e) {
+                    Toast.makeText(getActivity(), e.getMessage(), Toast.LENGTH_SHORT).show();
+                    passwordText.setText("");
+                }
             });
         });
         return ad;
@@ -107,6 +124,10 @@ public class PasswordGeneratorDialogFragment extends DialogFragment {
         if (!((CheckBox) getDialog().findViewById(R.id.pronounceable)).isChecked()) {
             preferences.add("s");
         }
+        if (!((CheckBox) getDialog().findViewById(R.id.lowercase)).isChecked()) {
+            preferences.add("L");
+        }
+
         EditText editText = getDialog().findViewById(R.id.lengthNumber);
         try {
             int length = Integer.valueOf(editText.getText().toString());
diff --git a/app/src/main/java/com/zeapo/pwdstore/pwgen/PasswordGenerator.kt b/app/src/main/java/com/zeapo/pwdstore/pwgen/PasswordGenerator.kt
index 3a7dcc27..6132d2dc 100644
--- a/app/src/main/java/com/zeapo/pwdstore/pwgen/PasswordGenerator.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/pwgen/PasswordGenerator.kt
@@ -1,15 +1,19 @@
 package com.zeapo.pwdstore.pwgen
 
 import android.content.Context
+import com.zeapo.pwdstore.R
 
 import java.util.ArrayList
 
+
+
 object PasswordGenerator {
     internal const val DIGITS = 0x0001
     internal const val UPPERS = 0x0002
     internal const val SYMBOLS = 0x0004
     internal const val AMBIGUOUS = 0x0008
     internal const val NO_VOWELS = 0x0010
+    internal const val LOWERS = 0x0020
 
     internal const val DIGITS_STR = "0123456789"
     internal const val UPPERS_STR = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
@@ -19,7 +23,7 @@ object PasswordGenerator {
     internal const val VOWELS_STR = "01aeiouyAEIOUY"
 
     // No a, c, n, h, H, C, 1, N
-    private const val pwOptions = "0ABsvy"
+    private const val pwOptions = "0ABsvyL"
 
     /**
      * Sets password generation preferences.
@@ -35,6 +39,7 @@ object PasswordGenerator {
      * <tr><td>s</td><td>generate completely random passwords</td></tr>
      * <tr><td>v</td><td>don't include vowels</td></tr>
      * <tr><td>y</td><td>include at least one symbol</td></tr>
+     * <tr><td>L</td><td>don't include lowercase letters</td></tr>
     </table> *
      * @param numArgv numerical options for password generation: length of
      * generated passwords followed by number of passwords to
@@ -76,17 +81,19 @@ object PasswordGenerator {
      * preferences file 'PasswordGenerator'
      * @return list of generated passwords
      */
+    @Throws(PasswordGenerator.PasswordGeneratorExeption::class)
     fun generate(ctx: Context): ArrayList<String> {
         val prefs = ctx.getSharedPreferences("PasswordGenerator", Context.MODE_PRIVATE)
 
         var phonemes = true
-        var pwgenFlags = DIGITS or UPPERS
+        var pwgenFlags = DIGITS or UPPERS or LOWERS
 
         for (option in pwOptions.toCharArray()) {
             if (prefs.getBoolean(option.toString(), false)) {
                 when (option) {
                     '0' -> pwgenFlags = pwgenFlags and DIGITS.inv()
                     'A' -> pwgenFlags = pwgenFlags and UPPERS.inv()
+                    'L' -> pwgenFlags = pwgenFlags and LOWERS.inv()
                     'B' -> pwgenFlags = pwgenFlags or AMBIGUOUS
                     's' -> phonemes = false
                     'y' -> pwgenFlags = pwgenFlags or SYMBOLS
@@ -99,15 +106,27 @@ object PasswordGenerator {
         }
 
         val length = prefs.getInt("length", 8)
-        if (length < 5) {
+        var numCategories = 0
+        var categories = pwgenFlags and AMBIGUOUS.inv()
+
+        while (categories != 0) {
+            if (categories and 1 == 1)
+                numCategories++
+            categories = categories shr 1
+        }
+        if (numCategories == 0) {
+            throw PasswordGeneratorExeption(ctx.resources.getString(R.string.pwgen_no_chars_error))
+        }
+        if (length < numCategories) {
+            throw PasswordGeneratorExeption(ctx.resources.getString(R.string.pwgen_length_too_short_error))
+        }
+        if ((pwgenFlags and UPPERS) == 0 && (pwgenFlags and LOWERS) == 0) { // Only digits and/or symbols
+            phonemes = false
+            pwgenFlags = pwgenFlags and AMBIGUOUS.inv()
+        } else if (length < 5) {
             phonemes = false
         }
-        if (length <= 2) {
-            pwgenFlags = pwgenFlags and UPPERS.inv()
-        }
-        if (length <= 1) {
-            pwgenFlags = pwgenFlags and DIGITS.inv()
-        }
+
 
         val passwords = ArrayList<String>()
         val num = prefs.getInt("num", 1)
@@ -120,5 +139,7 @@ object PasswordGenerator {
         }
         return passwords
     }
+
+    public class PasswordGeneratorExeption(string: String) : Exception(string)
 }
 
diff --git a/app/src/main/java/com/zeapo/pwdstore/pwgen/Phonemes.kt b/app/src/main/java/com/zeapo/pwdstore/pwgen/Phonemes.kt
index 4ec204bc..24d1edef 100644
--- a/app/src/main/java/com/zeapo/pwdstore/pwgen/Phonemes.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/pwgen/Phonemes.kt
@@ -65,6 +65,7 @@ internal object Phonemes {
      * <tr><td>1</td><td>include at least one uppercase letter</td></tr>
      * <tr><td>2</td><td>include at least one symbol</td></tr>
      * <tr><td>3</td><td>don't include ambiguous characters</td></tr>
+     * <tr><td>5</td><td>include at least one lowercase letter</td></tr>
     </table> *
      * @return the generated password
      */
@@ -119,7 +120,8 @@ internal object Phonemes {
 
                 // Handle UPPERS
                 if (pwFlags and PasswordGenerator.UPPERS > 0) {
-                    if ((first || flags and CONSONANT > 0) && RandomNumberGenerator.number(10) < 2) {
+                    if ((pwFlags and PasswordGenerator.LOWERS == 0) ||
+                            (first || flags and CONSONANT > 0) && RandomNumberGenerator.number(10) < 2) {
                         val index = password.length - length
                         password = password.substring(0, index) + str.toUpperCase()
                         featureFlags = featureFlags and PasswordGenerator.UPPERS.inv()
@@ -131,6 +133,17 @@ internal object Phonemes {
                     for (ambiguous in PasswordGenerator.AMBIGUOUS_STR.toCharArray()) {
                         if (password.contains(ambiguous.toString())) {
                             password = password.substring(0, curSize)
+
+                            // Still have upper letters
+                            if ((pwFlags and PasswordGenerator.UPPERS) > 0) {
+                                featureFlags = featureFlags or PasswordGenerator.UPPERS
+                                for (upper in PasswordGenerator.UPPERS_STR.toCharArray()) {
+                                    if (password.contains(upper.toString())) {
+                                        featureFlags = featureFlags and PasswordGenerator.UPPERS.inv()
+                                        break
+                                    }
+                                }
+                            }
                             break
                         }
                     }
diff --git a/app/src/main/java/com/zeapo/pwdstore/pwgen/RandomPasswordGenerator.kt b/app/src/main/java/com/zeapo/pwdstore/pwgen/RandomPasswordGenerator.kt
index 632fa579..5e565c0e 100644
--- a/app/src/main/java/com/zeapo/pwdstore/pwgen/RandomPasswordGenerator.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/pwgen/RandomPasswordGenerator.kt
@@ -15,6 +15,7 @@ internal object RandomPasswordGenerator {
      * <tr><td>2</td><td>include at least one symbol</td></tr>
      * <tr><td>3</td><td>don't include ambiguous characters</td></tr>
      * <tr><td>4</td><td>don't include vowels</td></tr>
+     * <tr><td>5</td><td>include at least one lowercase</td></tr>
     </table> *
      * @return the generated password
      */
@@ -33,7 +34,9 @@ internal object RandomPasswordGenerator {
         if (pwFlags and PasswordGenerator.UPPERS > 0) {
             bank += PasswordGenerator.UPPERS_STR
         }
-        bank += PasswordGenerator.LOWERS_STR
+        if (pwFlags and PasswordGenerator.LOWERS > 0) {
+            bank += PasswordGenerator.LOWERS_STR
+        }
         if (pwFlags and PasswordGenerator.SYMBOLS > 0) {
             bank += PasswordGenerator.SYMBOLS_STR
         }
@@ -65,8 +68,11 @@ internal object RandomPasswordGenerator {
                 if (PasswordGenerator.SYMBOLS_STR.contains(`val`)) {
                     featureFlags = featureFlags and PasswordGenerator.SYMBOLS.inv()
                 }
+                if (PasswordGenerator.LOWERS_STR.contains(`val`)) {
+                    featureFlags = featureFlags and PasswordGenerator.LOWERS.inv()
+                }
             }
-        } while (featureFlags and (PasswordGenerator.UPPERS or PasswordGenerator.DIGITS or PasswordGenerator.SYMBOLS) > 0)
+        } while (featureFlags and (PasswordGenerator.UPPERS or PasswordGenerator.DIGITS or PasswordGenerator.SYMBOLS or PasswordGenerator.LOWERS) > 0)
         return password
     }
 }
diff --git a/app/src/main/res/layout/fragment_pwgen.xml b/app/src/main/res/layout/fragment_pwgen.xml
index b5293920..eab23f7c 100644
--- a/app/src/main/res/layout/fragment_pwgen.xml
+++ b/app/src/main/res/layout/fragment_pwgen.xml
@@ -62,10 +62,10 @@
                     android:text="@string/pwgen_uppercase" />
 
                 <CheckBox
-                    android:id="@+id/ambiguous"
+                    android:id="@+id/lowercase"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
-                    android:text="@string/pwgen_ambiguous" />
+                    android:text="@string/pwgen_lowercase" />
 
             </LinearLayout>
 
@@ -97,6 +97,12 @@
                     android:layout_height="wrap_content"
                     android:text="@string/pwgen_pronounceable" />
 
+                <CheckBox
+                    android:id="@+id/ambiguous"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:text="@string/pwgen_ambiguous" />
+
             </LinearLayout>
         </LinearLayout>
     </LinearLayout>
diff --git a/app/src/main/res/values-es/strings.xml b/app/src/main/res/values-es/strings.xml
index 392be07f..84d1f7b9 100644
--- a/app/src/main/res/values-es/strings.xml
+++ b/app/src/main/res/values-es/strings.xml
@@ -166,8 +166,11 @@
     <string name="pwgen_numerals">Números</string>
     <string name="pwgen_symbols">Símbolos</string>
     <string name="pwgen_uppercase">Mayúsculas</string>
+    <string name="pwgen_lowercase">Minúsculas</string>
     <string name="pwgen_ambiguous">Caracteres ambiguos</string>
     <string name="pwgen_pronounceable">Pronunciable</string>
+    <string name="pwgen_no_chars_error">No se han incluído caracteres</string>
+    <string name="pwgen_length_too_short_error">Longitud demasiado corta para el criterio seleccionado</string>
 
     <!-- ssh keygen fragment -->
     <string name="ssh_keygen_length">Longitud</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 0b1afda1..ba0fed4c 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -180,8 +180,11 @@
     <string name="pwgen_numerals">Numerals</string>
     <string name="pwgen_symbols">Symbols</string>
     <string name="pwgen_uppercase">Uppercase</string>
+    <string name="pwgen_lowercase">Lowercase</string>
     <string name="pwgen_ambiguous">Ambiguous</string>
     <string name="pwgen_pronounceable">Pronounceable</string>
+    <string name="pwgen_no_chars_error">No characters included</string>
+    <string name="pwgen_length_too_short_error">Length too short for selected criteria</string>
 
     <!-- ssh keygen fragment -->
     <string name="ssh_keygen_length">Length</string>