diff --git a/girepository/girnode-private.h b/girepository/girnode-private.h
index 214e82bb2..e41678212 100644
--- a/girepository/girnode-private.h
+++ b/girepository/girnode-private.h
@@ -149,10 +149,10 @@ struct _GIIrNodeType
 
   uint8_t zero_terminated : 1;
   uint8_t has_length : 1;
-  int length;
+  unsigned int length;
   uint8_t has_size : 1;
-  int size;
-  int array_type;
+  size_t size;
+  GIArrayType array_type;
 
   GIIrNodeType *parameter_type1;  /* (owned) */
   GIIrNodeType *parameter_type2;  /* (owned) */
diff --git a/girepository/girnode.c b/girepository/girnode.c
index 2d0f818a0..eaad81bac 100644
--- a/girepository/girnode.c
+++ b/girepository/girnode.c
@@ -1243,7 +1243,7 @@ serialize_type (GIIrTypelibBuild *build,
           if (node->has_length)
             g_string_append_printf (str, "length=%d", node->length);
           else if (node->has_size)
-            g_string_append_printf (str, "fixed-size=%d", node->size);
+            g_string_append_printf (str, "fixed-size=%" G_GSIZE_FORMAT, node->size);
 
           if (node->zero_terminated)
             g_string_append_printf (str, "%szero-terminated=1",
diff --git a/girepository/girparser.c b/girepository/girparser.c
index 3924259a0..5de5177d4 100644
--- a/girepository/girparser.c
+++ b/girepository/girparser.c
@@ -2100,15 +2100,33 @@ start_type (GMarkupParseContext  *context,
       }
 
       if (typenode->array_type == GI_ARRAY_TYPE_C) {
+          guint64 parsed_uint;
+
           zero = find_attribute ("zero-terminated", attribute_names, attribute_values);
           len = find_attribute ("length", attribute_names, attribute_values);
           size = find_attribute ("fixed-size", attribute_names, attribute_values);
 
           typenode->has_length = len != NULL;
-          typenode->length = typenode->has_length ? atoi (len) : -1;
+          if (!typenode->has_length)
+            typenode->length = -1;
+          else if (g_ascii_string_to_unsigned (len, 10, 0, G_MAXUINT, &parsed_uint, error))
+            typenode->length = parsed_uint;
+          else
+            {
+              gi_ir_node_free ((GIIrNode *) typenode);
+              return FALSE;
+            }
 
           typenode->has_size = size != NULL;
-          typenode->size = typenode->has_size ? atoi (size) : -1;
+          if (!typenode->has_size)
+            typenode->size = -1;
+          else if (g_ascii_string_to_unsigned (size, 10, 0, G_MAXSIZE, &parsed_uint, error))
+            typenode->size = parsed_uint;
+          else
+            {
+              gi_ir_node_free ((GIIrNode *) typenode);
+              return FALSE;
+            }
 
           if (zero)
             typenode->zero_terminated = strcmp(zero, "1") == 0;