diff --git a/src/Humanizer.Tests.Shared/Localisation/bg/NumberToWordsTests.cs b/src/Humanizer.Tests.Shared/Localisation/bg/NumberToWordsTests.cs
index 814caea09..4a90bda45 100644
--- a/src/Humanizer.Tests.Shared/Localisation/bg/NumberToWordsTests.cs
+++ b/src/Humanizer.Tests.Shared/Localisation/bg/NumberToWordsTests.cs
@@ -8,7 +8,7 @@ public class NumberToWordsTests
 
         [Theory]
         [InlineData(0, "нула")]
-        [InlineData(1, "един")]
+        [InlineData(1, "едно")]
         [InlineData(10, "десет")]
         [InlineData(11, "единадесет")]
         [InlineData(12, "дванадесет")]
@@ -48,6 +48,7 @@ public class NumberToWordsTests
         [InlineData(4000210, "четири милиона двеста и десет")]
         [InlineData(5200, "пет хиляди и двеста")]
         [InlineData(1125000, "един милион и сто двадесет и пет хиляди")]
+        [InlineData(1000000000, "един милиард")]
         public void ToWordsBg(long number, string expected)
         {
             Assert.Equal(expected, number.ToWords());
diff --git a/src/Humanizer/Localisation/NumberToWords/BulgarianNumberToWordsConverter.cs b/src/Humanizer/Localisation/NumberToWords/BulgarianNumberToWordsConverter.cs
index e6a908f5f..679c8512c 100644
--- a/src/Humanizer/Localisation/NumberToWords/BulgarianNumberToWordsConverter.cs
+++ b/src/Humanizer/Localisation/NumberToWords/BulgarianNumberToWordsConverter.cs
@@ -7,7 +7,7 @@ internal class BulgarianNumberToWordsConverter : GenderedNumberToWordsConverter
     {
         private static readonly string[] UnitsMap =
         {
-            "нула", "един", "две", "три", "четири", "пет", "шест", "седем", "осем", "девет", "десет", "единадесет",
+            "нула", "едно", "две", "три", "четири", "пет", "шест", "седем", "осем", "девет", "десет", "единадесет",
             "дванадесет", "тринадесет", "четиринадесет", "петнадесет", "шестнадесет", "седемнадесет", "осемнадесет",
             "деветнадесет"
         };
@@ -24,14 +24,12 @@ internal class BulgarianNumberToWordsConverter : GenderedNumberToWordsConverter
             "осемстотин", "деветстотин"
         };
 
-
         private static readonly string[] HundredsOrdinalMap =
         {
             String.Empty, "стот", "двест", "трист", "четиристот", "петстот", "шестстот", "седемстот", "осемстот",
             "деветстот"
         };
 
-
         private static readonly string[] UnitsOrdinal =
         {
             string.Empty, "първ", "втор", "трет", "четвърт", "пет", "шест", "седм", "осм", "девeт", "десeт",
@@ -77,8 +75,7 @@ private string Convert(long input, GrammaticalGender gender, bool isOrdinal, boo
 
             if ((input / 1000000000) > 0)
             {
-                parts.Add(Convert(input / 1000000000, gender, false) +
-                          $" {(input < 2000000000 ? "милиард" : "милиарда")}");
+                parts.Add(input < 2000000000 ? "един милиард" : Convert(input / 1000000000, gender, false) + " милиарда");
 
                 if (isOrdinal)
                     lastOrdinalSubstitution = Convert(input / 1000000000, gender, false) + " милиард" +
@@ -88,7 +85,7 @@ private string Convert(long input, GrammaticalGender gender, bool isOrdinal, boo
 
             if ((input / 1000000) > 0)
             {
-                parts.Add(Convert(input / 1000000, gender, false) + $" {(input < 2000000 ? "милион" : "милиона")}");
+                parts.Add(input < 2000000 ? "един милион" : Convert(input / 1000000, gender, false) + " милиона");
 
                 if (isOrdinal)
                     lastOrdinalSubstitution = Convert(input / 1000000, gender, false) + " милион" +