diff --git a/externals/vts-libs b/externals/vts-libs
index f5bff04..a2c1516 160000
--- a/externals/vts-libs
+++ b/externals/vts-libs
@@ -1 +1 @@
-Subproject commit f5bff04cde00ccb9cda5f57681cf9a535b036ffe
+Subproject commit a2c15165da0667535265e97df9ad5a1ae6f1907f
diff --git a/mapproxy/src/mapproxy/CMakeLists.txt b/mapproxy/src/mapproxy/CMakeLists.txt
index e6c2c46..8637980 100644
--- a/mapproxy/src/mapproxy/CMakeLists.txt
+++ b/mapproxy/src/mapproxy/CMakeLists.txt
@@ -68,7 +68,7 @@ define_module(LIBRARY mapproxy-core
   DEPENDS
   qmf semantic
   pysupport pydbglog
-  vts-libs>=2.4 http>=1.0 geo>=1.28 geometry>=1.7
+  vts-libs>=2.18 http>=1.0 geo>=1.28 geometry>=1.7
   jsoncpp>=2.1
 
   Boost_SERIALIZATION