diff --git a/src/web/drive_properties.json b/src/web/drive_properties.json
index 88f620ad..1e39db53 100644
--- a/src/web/drive_properties.json
+++ b/src/web/drive_properties.json
@@ -77,7 +77,7 @@
     "product": "1325",
     "revision": "",
     "block_size": 512,
-    "size": 138412032,
+    "size": 69206016,
     "name": "Micropolis 1325",
     "file_type": "hds",
     "description": "Largest predefined on SunOS 2; Microp 1325 is actually an ESDI disk on an adapter.",
@@ -89,7 +89,7 @@
     "product": "1588T",
     "revision": "",
     "block_size": 512,
-    "size": 333742080,
+    "size": 166871040,
     "name": "Micropolis 1588-15",
     "file_type": "hds",
     "description": "Largest predefined on SunOS 3/4 (Sun-3)",