diff --git a/pyfaidx/__init__.py b/pyfaidx/__init__.py
index 38edcde..5f39ad1 100644
--- a/pyfaidx/__init__.py
+++ b/pyfaidx/__init__.py
@@ -342,7 +342,7 @@ def __init__(self, filename, default_seq=None, key_function=lambda x: x,
         self.as_raw = as_raw
         self.default_seq = default_seq
         if self._bgzf and self.default_seq is not None:
-            raise UnsupportedCompressionFormat("The default_seq argument is not supported with using BGZF compression. Please decompress your FASTA file and try again.")
+            raise FetchError("The default_seq argument is not supported with using BGZF compression. Please decompress your FASTA file and try again.")
         if self._bgzf:
             self.strict_bounds = True
         else: