diff --git a/doomsday/config.pri b/doomsday/config.pri
index 33593be9ca..1a0c3e6495 100644
--- a/doomsday/config.pri
+++ b/doomsday/config.pri
@@ -86,9 +86,12 @@ deng_fakememoryzone: DEFINES += LIBDENG_FAKE_MEMORY_ZONE
 
 # Check for Qt 5.
 greaterThan(QT_MAJOR_VERSION, 4) {
-    CONFIG += deng_qt5 c++11
+    CONFIG += deng_qt5
 }
 
+# Enable C++11 everywhere.
+CONFIG += c++11
+
 # Check for a 64-bit compiler.
 contains(QMAKE_HOST.arch, x86_64) {
     echo(64-bit architecture detected.)
diff --git a/doomsday/config_unix_any.pri b/doomsday/config_unix_any.pri
index 4b8c87b1b0..7d3efd6d1e 100644
--- a/doomsday/config_unix_any.pri
+++ b/doomsday/config_unix_any.pri
@@ -25,7 +25,7 @@ deng_debuginfo {
     QMAKE_CFLAGS_WARN_ON += -Wno-tautological-compare
 }
 
-deng_qt5 {
+c++11 {
     QMAKE_CXXFLAGS += -std=c++11
 }
 
diff --git a/doomsday/libcore/include/de/libcore.h b/doomsday/libcore/include/de/libcore.h
index a671a0b167..5a79cfb1d4 100644
--- a/doomsday/libcore/include/de/libcore.h
+++ b/doomsday/libcore/include/de/libcore.h
@@ -73,7 +73,7 @@
 #if defined(__cplusplus) && !defined(DENG2_C_API_ONLY)
 #  define DENG2_USE_QT
 #  include <typeinfo>
-#  include <memory>  // auto_ptr
+#  include <memory>  // unique_ptr, shared_ptr
 #  include <cstring> // memset
 #endif