diff --git a/include/QF/qfplist.h b/include/QF/qfplist.h
index 011090818..3fdfa7825 100644
--- a/include/QF/qfplist.h
+++ b/include/QF/qfplist.h
@@ -129,7 +129,7 @@ char *PL_WritePropertyList (plitem_t *pl);
 	\param item The object
 	\return the type of the object
 */
-pltype_t PL_Type (plitem_t *item) __attribute__((pure));
+pltype_t PL_Type (const plitem_t *item) __attribute__((pure));
 
 /** Retrieve the line number of an object.
 
@@ -137,7 +137,7 @@ pltype_t PL_Type (plitem_t *item) __attribute__((pure));
 	\return the line number on which the object began, or 0 if not from a
 			string
 */
-int PL_Line (plitem_t *item) __attribute__((pure));
+int PL_Line (const plitem_t *item) __attribute__((pure));
 
 /** Retrieve a string from a string object.
 
diff --git a/libs/util/qfplist.c b/libs/util/qfplist.c
index ab24a9499..2b96ecdf4 100644
--- a/libs/util/qfplist.c
+++ b/libs/util/qfplist.c
@@ -1051,13 +1051,13 @@ PL_WritePropertyList (plitem_t *pl)
 }
 
 VISIBLE pltype_t
-PL_Type (plitem_t *item)
+PL_Type (const plitem_t *item)
 {
 	return item->type;
 }
 
 VISIBLE int
-PL_Line (plitem_t *item)
+PL_Line (const plitem_t *item)
 {
 	return item->line;
 }