diff --git a/rbgen.in b/rbgen.in
index 3f52eb2..ae7e991 100644
--- a/rbgen.in
+++ b/rbgen.in
@@ -78,7 +78,7 @@
                 if line[0] == "\n":
                     continue
                 elif startswith(line, "%%rbgen"):
-		    fpout.write("#define RB_CUSTOMIZE\n")
+                    fpout.write("#define RB_CUSTOMIZE\n")
                     if not rb_type:
                         error("%type directive is required.")
                     else:
@@ -153,9 +153,9 @@
     lines = 1;
     skelpath = [".", "@prefix@/share/@PACKAGE@" "/share/redblack"]
     for (switch, val) in options:
-	if (switch == '-l'):
-	    lines = 0
-	elif (switch == '-S'):
+        if (switch == '-l'):
+            lines = 0
+        elif (switch == '-S'):
             skeldir = val
 
     for skeldir in skelpath: