diff --git a/block_test.go b/block_test.go
index a97d01a..5231a21 100644
--- a/block_test.go
+++ b/block_test.go
@@ -265,6 +265,13 @@ func TestBlockErrors(t *testing.T) {
 	}
 	block100000Bytes := block100000Buf.Bytes()
 
+	// Create a new block from the encoded bytes.
+	b, err := btcutil.NewBlockFromBytes(block100000Bytes, pver)
+	if err != nil {
+		t.Errorf("NewBlockFromBytes: %v", err)
+		return
+	}
+
 	// Truncate the block byte buffer to force errors.
 	shortBytes := block100000Bytes[:80]
 	_, err = btcutil.NewBlockFromBytes(shortBytes, pver)
@@ -273,6 +280,18 @@ func TestBlockErrors(t *testing.T) {
 			"got %v, want %v", err, io.EOF)
 		return
 	}
+
+	// Ensure TxSha returns expected error on invalid indices.
+	_, err = b.TxSha(-1)
+	if _, ok := err.(btcutil.OutOfRangeError); !ok {
+		t.Errorf("TxSha: wrong error - got: %v <%T>, "+
+			"want: <%T>", err, err, btcutil.OutOfRangeError(""))
+	}
+	_, err = b.TxSha(len(Block100000.Transactions) + 1)
+	if _, ok := err.(btcutil.OutOfRangeError); !ok {
+		t.Errorf("TxSha: wrong error - got: %v <%T>, "+
+			"want: <%T>", err, err, btcutil.OutOfRangeError(""))
+	}
 }
 
 // Block100000 defines block 100,000 of the block chain.  It is used to
diff --git a/test_coverage.txt b/test_coverage.txt
index 61b3e61..0be2a59 100644
--- a/test_coverage.txt
+++ b/test_coverage.txt
@@ -1,4 +1,5 @@
 
+github.com/conformal/btcutil/block.go	 Block.TxSha			 100.00% (11/11)
 github.com/conformal/btcutil/block.go	 Block.TxShas			 100.00% (10/10)
 github.com/conformal/btcutil/block.go	 NewBlockFromBytes		 100.00% (7/7)
 github.com/conformal/btcutil/block.go	 Block.Sha			 100.00% (5/5)
@@ -9,8 +10,7 @@ github.com/conformal/btcutil/block.go	 Block.Height			 100.00% (1/1)
 github.com/conformal/btcutil/block.go	 Block.SetHeight		 100.00% (1/1)
 github.com/conformal/btcutil/block.go	 NewBlock			 100.00% (1/1)
 github.com/conformal/btcutil/block.go	 Block.Bytes			 88.89% (8/9)
-github.com/conformal/btcutil/block.go	 Block.TxSha			 81.82% (9/11)
 github.com/conformal/btcutil/block.go	 Block.TxLoc			 77.78% (7/9)
 github.com/conformal/btcutil/block.go	 OutOfRangeError.Error		 0.00% (0/1)
-github.com/conformal/btcutil		 -------------------------	 89.66% (52/58)
+github.com/conformal/btcutil		 -------------------------	 93.10% (54/58)