diff --git a/CHANGES b/CHANGES
index eae6157271..b701d5923b 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+5018.	[bug]		Fix incorrect sizeof arguments in lib/isc/pk11.c.
+			[GL !588]
+
 5017.	[bug]		lib/isc/pk11.c failed to unlink the session before
 			releasing the lock which is unsafe. [GL !589]
 
diff --git a/lib/isc/pk11.c b/lib/isc/pk11.c
index f3835b6641..4624e94d47 100644
--- a/lib/isc/pk11.c
+++ b/lib/isc/pk11.c
@@ -484,7 +484,7 @@ scan_slots(void) {
 	/* it's not an error if we didn't find any providers */
 	if (slotCount == 0)
 		return;
-	slotList = pk11_mem_get(sizeof(CK_SLOT_ID_PTR) * slotCount);
+	slotList = pk11_mem_get(sizeof(CK_SLOT_ID) * slotCount);
 	RUNTIME_CHECK(slotList != NULL);
 	PK11_FATALCHECK(pkcs_C_GetSlotList, (CK_FALSE, slotList, &slotCount));
 
@@ -671,7 +671,7 @@ scan_slots(void) {
 	}
 
 	if (slotList != NULL) {
-		pk11_mem_put(slotList, sizeof(CK_SLOT_ID_PTR) * slotCount);
+		pk11_mem_put(slotList, sizeof(CK_SLOT_ID) * slotCount);
 	}
 }