diff --git a/src/XrdCeph.cmake b/src/XrdCeph.cmake
index ace2f5921f5..b692b9001fe 100644
--- a/src/XrdCeph.cmake
+++ b/src/XrdCeph.cmake
@@ -18,7 +18,15 @@ add_library(
 # needed during the transition between ceph giant and ceph hammer
 # for object listing API
 set_property(SOURCE XrdCeph/XrdCephPosix.cc
-             PROPERTY COMPILE_FLAGS " -Wno-deprecated-declarations")
+  PROPERTY COMPILE_FLAGS " -Wno-deprecated-declarations")
+
+# needed for librados when as C++11 is enabled
+include(CheckCXXCompilerFlag)
+CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
+IF (COMPILER_SUPPORTS_CXX11)
+  set_property(SOURCE XrdCeph/XrdCephPosix.cc APPEND_STRING
+    PROPERTY COMPILE_FLAGS " -std=c++11")
+ENDIF()
 
 target_link_libraries(
   XrdCephPosix
diff --git a/src/XrdCeph/XrdCephPosix.cc b/src/XrdCeph/XrdCephPosix.cc
index 99bacef5aa4..644490ca00a 100644
--- a/src/XrdCeph/XrdCephPosix.cc
+++ b/src/XrdCeph/XrdCephPosix.cc
@@ -220,15 +220,15 @@ static int fillCephStripeUnit(const std::string &params, unsigned int offset, Xr
       if (NULL != env) {
         char* cStripeUnit = env->Get("cephStripeUnit");
         if (0 != cStripeUnit) {
-          file.stripeUnit = stoull(cStripeUnit);
+          file.stripeUnit = ::stoull(cStripeUnit);
         }
       }
     } else {
-      file.stripeUnit = stoull(params.substr(offset));
+      file.stripeUnit = ::stoull(params.substr(offset));
     }
     return params.size();
   } else {
-    file.stripeUnit = stoull(params.substr(offset, comPos-offset));
+    file.stripeUnit = ::stoull(params.substr(offset, comPos-offset));
     return comPos+1;
   }
 }
@@ -244,11 +244,11 @@ static void fillCephObjectSize(const std::string &params, unsigned int offset, X
     if (NULL != env) {
       char* cObjectSize = env->Get("cephObjectSize");
       if (0 != cObjectSize) {
-        file.objectSize = stoull(cObjectSize);
+        file.objectSize = ::stoull(cObjectSize);
       }
     }
   } else {
-    file.objectSize = stoull(params.substr(offset));
+    file.objectSize = ::stoull(params.substr(offset));
   }
 }