diff --git a/git-compat-util.h b/git-compat-util.h
index 9a64998b24..b904af3f22 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -844,6 +844,7 @@ extern FILE *fopen_or_warn(const char *path, const char *mode);
 #define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)
 
 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
+#define CALLOC_ARRAY(x, alloc) (x) = xcalloc((alloc), sizeof(*(x)));
 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
 
 #define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \
diff --git a/pack-objects.h b/pack-objects.h
index 741e6f862d..a89f76e5b1 100644
--- a/pack-objects.h
+++ b/pack-objects.h
@@ -364,7 +364,7 @@ static inline void oe_set_tree_depth(struct packing_data *pack,
 				     unsigned int tree_depth)
 {
 	if (!pack->tree_depth)
-		ALLOC_ARRAY(pack->tree_depth, pack->nr_alloc);
+		CALLOC_ARRAY(pack->tree_depth, pack->nr_alloc);
 	pack->tree_depth[e - pack->objects] = tree_depth;
 }
 
@@ -381,7 +381,7 @@ static inline void oe_set_layer(struct packing_data *pack,
 				unsigned char layer)
 {
 	if (!pack->layer)
-		ALLOC_ARRAY(pack->layer, pack->nr_alloc);
+		CALLOC_ARRAY(pack->layer, pack->nr_alloc);
 	pack->layer[e - pack->objects] = layer;
 }