diff --git a/meta/classes/dpkg-prebuilt.bbclass b/meta/classes/dpkg-prebuilt.bbclass
index a6187a07..ecf0d383 100644
--- a/meta/classes/dpkg-prebuilt.bbclass
+++ b/meta/classes/dpkg-prebuilt.bbclass
@@ -7,13 +7,16 @@ inherit dpkg-base
 
 python do_unpack:prepend() {
     # enforce unpack=false
-    src_uri = (d.getVar('SRC_URI', False) or '').split()
-    if len(src_uri) == 0:
+    src_uri_raw = d.getVar('SRC_URI', False)
+    src_uri_exp = (d.getVar('SRC_URI', True) or '').split()
+    if len(src_uri_exp) == 0:
         return
     def ensure_unpack_false(uri):
         return ';'.join([x for x in uri.split(';') if not x.startswith('unpack=')] + ['unpack=false'])
-    src_uri = [ensure_unpack_false(uri) for uri in src_uri]
+    src_uri = [ensure_unpack_false(uri) for uri in src_uri_exp]
     d.setVar('SRC_URI', ' '.join(src_uri))
+    if src_uri_raw:
+        d.appendVarFlag('SRC_URI', 'vardepvalue', src_uri_raw)
 }
 
 # also breaks inherited (from dpkg-base) dependency on sbuild_chroot