diff --git a/doomsday/sdk/libcore/src/core/app.cpp b/doomsday/sdk/libcore/src/core/app.cpp
index 1551250844..456d58e73e 100644
--- a/doomsday/sdk/libcore/src/core/app.cpp
+++ b/doomsday/sdk/libcore/src/core/app.cpp
@@ -162,6 +162,8 @@ DENG2_PIMPL(App)
         #ifdef UNIX
         {
             // We wish to use U.S. English formatting for time and numbers (in libc).
+            setenv("LC_ALL", "en_US.UTF-8", 1);
+            setenv("LC_NUMERIC", "C", 1);
             setlocale(LC_ALL, "en_US.UTF-8");
             setlocale(LC_NUMERIC, "C");
         }