diff --git a/mcs/class/corlib/System.Text/ASCIIEncoding.cs b/mcs/class/corlib/System.Text/ASCIIEncoding.cs
index b2d2801c43479..933c22c4b4858 100644
--- a/mcs/class/corlib/System.Text/ASCIIEncoding.cs
+++ b/mcs/class/corlib/System.Text/ASCIIEncoding.cs
@@ -223,6 +223,18 @@ public override int GetCharCount (byte[] bytes, int index, int count)
 	// Get the characters that result from decoding a byte buffer.
 	public override int GetChars (byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex)
 	{
+#if NET_2_0
+// well, yes, I know this #if is ugly, but I think it is the simplest switch.
+		DecoderFallbackBuffer buffer = null;
+		return GetChars (bytes, byteIndex, byteCount, chars,
+			charIndex, ref buffer);
+	}
+
+	int GetChars (byte[] bytes, int byteIndex, int byteCount,
+		      char[] chars, int charIndex,
+		      ref DecoderFallbackBuffer buffer)
+	{
+#endif
 		if (bytes == null)
 			throw new ArgumentNullException ("bytes");
 		if (chars == null) 
@@ -242,8 +254,17 @@ public override int GetChars (byte[] bytes, int byteIndex, int byteCount, char[]
 			char c = (char) bytes [byteIndex++];
 			if (c < '\x80')
 				chars [charIndex++] = c;
-			else
+			else {
+#if NET_2_0
+				if (buffer == null)
+					buffer = DecoderFallback.CreateFallbackBuffer ();
+				buffer.Fallback (bytes, byteIndex);
+				while (buffer.Remaining > 0)
+					chars [charIndex++] = buffer.GetNextChar ();
+#else
 				chars [charIndex++] = '?';
+#endif
+			}
 		}
 		return byteCount;
 	}
diff --git a/mcs/class/corlib/System.Text/ChangeLog b/mcs/class/corlib/System.Text/ChangeLog
index db76dffc5eed2..500695715ffb3 100644
--- a/mcs/class/corlib/System.Text/ChangeLog
+++ b/mcs/class/corlib/System.Text/ChangeLog
@@ -1,3 +1,7 @@
+2006-04-13  Atsushi Enomoto  <atsushi@ximian.com>
+
+	* ASCIIEncoding.cs : 2.0 decoder fallback support was missing.
+
 2006-03-30  Atsushi Enomoto  <atsushi@ximian.com>
 
 	* Encoder.cs, Decoder.cs : implemented Convert(). Also added argument
diff --git a/mcs/class/corlib/Test/System.Text/ASCIIEncodingTest.cs b/mcs/class/corlib/Test/System.Text/ASCIIEncodingTest.cs
index e848ac8261caf..11a6065ab399a 100644
--- a/mcs/class/corlib/Test/System.Text/ASCIIEncodingTest.cs
+++ b/mcs/class/corlib/Test/System.Text/ASCIIEncodingTest.cs
@@ -171,6 +171,16 @@ public void TestZero ()
 			AssertEquals ("#02", encoding.GetString (new byte [0], 0, 0), "");
 		}
 
+#if NET_2_0
+		[Test]
+		[ExpectedException (typeof (DecoderFallbackException))]
+		public void DecoderFallback ()
+		{
+			Encoding e = Encoding.ASCII.Clone () as Encoding;
+			e.DecoderFallback = new DecoderExceptionFallback ();
+			e.GetChars (new byte [] {0x80});
+		}
+#endif
 	}
 
 }
diff --git a/mcs/class/corlib/Test/System.Text/ChangeLog b/mcs/class/corlib/Test/System.Text/ChangeLog
index f495f5c30b29f..a3eeeb6e02b83 100644
--- a/mcs/class/corlib/Test/System.Text/ChangeLog
+++ b/mcs/class/corlib/Test/System.Text/ChangeLog
@@ -1,3 +1,7 @@
+2006-04-13  Atsushi Enomoto  <atsushi@ximian.com>
+
+	* ASCIIEncodingTest.cs : added DecoderFallback().
+
 2006-03-30  Atsushi Enomoto  <atsushi@ximian.com>
 
 	* EncoderTest.cs, DecoderTest.cs : new tests, for Convert().