diff --git a/bin/boto-rsync b/bin/boto-rsync
index 76278b2..7ed8e80 100644
--- a/bin/boto-rsync
+++ b/bin/boto-rsync
@@ -181,7 +181,22 @@ def main():
     num_cb = 10
     rename = False
     copy_file = True
-    
+
+    # Boto < 2.0 missing __version__, hence try/except
+    # S3 encryption support present in 2.1.0 and later
+    desired_boto = '2.1.0'
+    boto_err = 'Boto version %s or later is required\n' % desired_boto
+    boto_err += 'Try: sudo easy_install boto\n'
+
+    try:
+        from pkg_resources import parse_version
+        if parse_version(boto.__version__) < parse_version(desired_boto):
+            sys.stdout.write(boto_err)
+            sys.exit(1)
+    except (AttributeError, NameError):
+        sys.stdout.write(boto_err)
+        sys.exit(1)
+
     parser = argparse.ArgumentParser(
         formatter_class=argparse.RawDescriptionHelpFormatter,
         usage='%(prog)s [OPTIONS] SOURCE DESTINATION',