diff --git a/WINGs/WINGs/WUtil.h b/WINGs/WINGs/WUtil.h
index 347e70ee..9569b325 100644
--- a/WINGs/WINGs/WUtil.h
+++ b/WINGs/WINGs/WUtil.h
@@ -142,7 +142,7 @@ typedef int WMCompareDataProc(const void *item1, const void *item2);
 typedef void WMFreeDataProc(void *data);
 
 /* Used by WMBag or WMArray for matching data */
-typedef int WMMatchDataProc(void *item, void *cdata);
+typedef int WMMatchDataProc(const void *item, const void *cdata);
 
 
 
diff --git a/WINGs/host.c b/WINGs/host.c
index 53f94074..aeee6c73 100644
--- a/WINGs/host.c
+++ b/WINGs/host.c
@@ -218,7 +218,7 @@ void WMFlushHostCache()
 	}
 }
 
-static int matchAddress(void *item, void *cdata)
+static int matchAddress(const void *item, const void *cdata)
 {
 	return (strcmp((char *)item, (char *)cdata) == 0);
 }
diff --git a/WINGs/notification.c b/WINGs/notification.c
index e3af3df3..3febb2c7 100644
--- a/WINGs/notification.c
+++ b/WINGs/notification.c
@@ -384,17 +384,17 @@ void WMEnqueueNotification(WMNotificationQueue * queue, WMNotification * notific
 #define NOTIF ((WMNotification*)cdata)
 #define ITEM  ((WMNotification*)item)
 
-static int matchSenderAndName(void *item, void *cdata)
+static int matchSenderAndName(const void *item, const void *cdata)
 {
 	return (NOTIF->object == ITEM->object && strcmp(NOTIF->name, ITEM->name) == 0);
 }
 
-static int matchSender(void *item, void *cdata)
+static int matchSender(const void *item, const void *cdata)
 {
 	return (NOTIF->object == ITEM->object);
 }
 
-static int matchName(void *item, void *cdata)
+static int matchName(const void *item, const void *cdata)
 {
 	return (strcmp(NOTIF->name, ITEM->name) == 0);
 }
diff --git a/WINGs/tree.c b/WINGs/tree.c
index 5781588b..45c1497f 100644
--- a/WINGs/tree.c
+++ b/WINGs/tree.c
@@ -125,7 +125,7 @@ void WMDeleteLeafForTreeNode(WMTreeNode * aNode, int index)
 	WMDeleteFromArray(aNode->leaves, index);
 }
 
-static int sameData(void *item, void *data)
+static int sameData(const void *item, const void *data)
 {
 	return (((WMTreeNode *) item)->data == data);
 }
diff --git a/WINGs/wbox.c b/WINGs/wbox.c
index b5ee1bc8..2c7d9490 100644
--- a/WINGs/wbox.c
+++ b/WINGs/wbox.c
@@ -194,7 +194,7 @@ void WMAddBoxSubviewAtEnd(WMBox * bPtr, WMView * view, Bool expand, Bool fill, i
 	rearrange(bPtr);
 }
 
-static int matchView(void *item, void *cdata)
+static int matchView(const void *item, const void *cdata)
 {
 	return (((SubviewItem *) item)->view == (WMView *) cdata);
 }
diff --git a/WINGs/wevent.c b/WINGs/wevent.c
index 6865838e..8f7a5b6f 100644
--- a/WINGs/wevent.c
+++ b/WINGs/wevent.c
@@ -78,7 +78,7 @@ void WMCreateEventHandler(WMView * view, unsigned long mask, WMEventProc * event
 	WMAddToArray(view->eventHandlers, hPtr);
 }
 
-static int matchHandler(void *item, void *cdata)
+static int matchHandler(const void *item, const void *cdata)
 {
 #define H1 ((W_EventHandler*)item)
 #define H2 ((W_EventHandler*)cdata)
diff --git a/WINGs/wlist.c b/WINGs/wlist.c
index 759fe62e..f8fbde80 100644
--- a/WINGs/wlist.c
+++ b/WINGs/wlist.c
@@ -638,7 +638,7 @@ static void handleEvents(XEvent * event, void *data)
 	}
 }
 
-static int matchTitle(void *item, void *title)
+static int matchTitle(const void *item, const void *title)
 {
 	return (strcmp(((WMListItem *) item)->text, (char *)title) == 0 ? 1 : 0);
 }
diff --git a/src/dock.c b/src/dock.c
index 46d45f4a..0e932e8a 100644
--- a/src/dock.c
+++ b/src/dock.c
@@ -195,7 +195,7 @@ static void toggleLoweredCallback(WMenu * menu, WMenuEntry * entry)
 	wMenuPaint(menu);
 }
 
-static int matchWindow(void *item, void *cdata)
+static int matchWindow(const void *item, const void *cdata)
 {
 	return (((WFakeGroupLeader *) item)->leader == (Window) cdata);
 }
diff --git a/src/event.c b/src/event.c
index 618a5e9e..47ad7173 100644
--- a/src/event.c
+++ b/src/event.c
@@ -529,7 +529,7 @@ static void saveTimestamp(XEvent * event)
 	}
 }
 
-static int matchWindow(void *item, void *cdata)
+static int matchWindow(const void *item, const void *cdata)
 {
 	return (((WFakeGroupLeader *) item)->origLeader == (Window) cdata);
 }
diff --git a/src/window.c b/src/window.c
index 22f97b4a..76554986 100644
--- a/src/window.c
+++ b/src/window.c
@@ -564,7 +564,7 @@ static Window createFakeWindowGroupLeader(WScreen *scr, Window win, char *instan
 	return leader;
 }
 
-static int matchIdentifier(void *item, void *cdata)
+static int matchIdentifier(const void *item, const void *cdata)
 {
 	return (strcmp(((WFakeGroupLeader *) item)->identifier, (char *)cdata) == 0);
 }