diff --git a/src/conf_regex.h b/src/conf_regex.h
index e52cc07..d87073a 100644
--- a/src/conf_regex.h
+++ b/src/conf_regex.h
@@ -8,7 +8,7 @@
  * given directive.
  */
 #define DIGIT "[0-9]"
-#define SPACE "[ \t]"
+#define SPACE "[ \\t]"
 #define WS SPACE "+"
 #define STR "\"([^\"]+)\""
 #define BOOL "(yes|on|no|off)"