diff --git a/girepository/girwriter.c b/girepository/girwriter.c
index 22b366bd2..6c52ed054 100644
--- a/girepository/girwriter.c
+++ b/girepository/girwriter.c
@@ -244,7 +244,7 @@ write_type_info (const char *ns,
     }
   else if (tag == GI_TYPE_TAG_ARRAY)
     {
-      int length;
+      gssize length;
       gssize size;
       const char *name = NULL;
 
@@ -273,7 +273,7 @@ write_type_info (const char *ns,
 
       length = gi_type_info_get_array_length_index (info);
       if (length >= 0)
-        xml_printf (file, " length=\"%d\"", length);
+        xml_printf (file, " length=\"%" G_GSSIZE_FORMAT "\"", length);
 
       size = gi_type_info_get_array_fixed_size (info);
       if (size >= 0)
diff --git a/girepository/gitypeinfo.c b/girepository/gitypeinfo.c
index 349e0f879..5086ec2a2 100644
--- a/girepository/gitypeinfo.c
+++ b/girepository/gitypeinfo.c
@@ -241,7 +241,7 @@ gi_type_info_get_interface (GITypeInfo *info)
  *   or it has no length argument
  * Since: 2.80
  */
-int
+gssize
 gi_type_info_get_array_length_index (GITypeInfo *info)
 {
   GIRealInfo *rinfo = (GIRealInfo *)info;
diff --git a/girepository/gitypeinfo.h b/girepository/gitypeinfo.h
index 56a5c7c24..d12790a36 100644
--- a/girepository/gitypeinfo.h
+++ b/girepository/gitypeinfo.h
@@ -96,7 +96,7 @@ GI_AVAILABLE_IN_ALL
 GIBaseInfo *           gi_type_info_get_interface       (GITypeInfo *info);
 
 GI_AVAILABLE_IN_ALL
-int                    gi_type_info_get_array_length_index (GITypeInfo *info);
+gssize                 gi_type_info_get_array_length_index (GITypeInfo *info);
 
 GI_AVAILABLE_IN_ALL
 gssize                 gi_type_info_get_array_fixed_size (GITypeInfo *info);