diff --git a/include/boost/preprocessor/facilities/is_empty_or_1.hpp b/include/boost/preprocessor/facilities/is_empty_or_1.hpp
index 0809612..1d35be5 100644
--- a/include/boost/preprocessor/facilities/is_empty_or_1.hpp
+++ b/include/boost/preprocessor/facilities/is_empty_or_1.hpp
@@ -21,11 +21,11 @@
 # /* BOOST_PP_IS_EMPTY_OR_1 */
 #
 # define BOOST_PP_IS_EMPTY_OR_1(x) \
-	BOOST_PP_IIF( \
-		BOOST_PP_IS_EMPTY(x BOOST_PP_EMPTY()), \
-		1 BOOST_PP_EMPTY, \
-		BOOST_PP_IS_1 \
-	)(x) \
-	/**/
+    BOOST_PP_IIF( \
+        BOOST_PP_IS_EMPTY(x BOOST_PP_EMPTY()), \
+        1 BOOST_PP_EMPTY, \
+        BOOST_PP_IS_1 \
+    )(x) \
+    /**/
 #
 # endif