diff --git a/pjsip-asterisk.rb b/pjsip-asterisk.rb
index 2834457..21be3a0 100644
--- a/pjsip-asterisk.rb
+++ b/pjsip-asterisk.rb
@@ -20,7 +20,7 @@ def install
     # Build for not-debug
     ENV["CFLAGS"] = "-O2 -DNDEBUG"
 
-    config_site = <<-EOF.undent
+    config_site = <<-EOF
       #include <sys/select.h>
 
       /*