diff --git a/Include/pgenheaders.h b/Include/pgenheaders.h
index 4843de6..dbc5e0a 100644
--- a/Include/pgenheaders.h
+++ b/Include/pgenheaders.h
@@ -10,9 +10,9 @@
 #include "Python.h"
 
 PyAPI_FUNC(void) PySys_WriteStdout(const char *format, ...)
-			Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
+                        Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
 PyAPI_FUNC(void) PySys_WriteStderr(const char *format, ...)
-			Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
+                        Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
 
 #define addarc _Py_addarc
 #define addbit _Py_addbit