diff --git a/include/asm-s390/ccwdev.h b/include/asm-s390/ccwdev.h
index 12456cb..58c70ac 100644
--- a/include/asm-s390/ccwdev.h
+++ b/include/asm-s390/ccwdev.h
@@ -63,7 +63,7 @@
 		return id;
 	}
 
-	return 0;
+	return NULL;
 }
 
 /* The struct ccw device is our replacement for the globally accessible
diff --git a/include/asm-s390/pgalloc.h b/include/asm-s390/pgalloc.h
index 3002fda..a78e853 100644
--- a/include/asm-s390/pgalloc.h
+++ b/include/asm-s390/pgalloc.h
@@ -142,7 +142,7 @@
 	pte_t *pte = pte_alloc_one_kernel(mm, vmaddr);
 	if (pte)
 		return virt_to_page(pte);
-	return 0;
+	return NULL;
 }
 
 static inline void pte_free_kernel(pte_t *pte)