diff --git a/source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Environment/Environment.cpp b/source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Environment/Environment.cpp
index d4796ec..d0e8c9a 100644
--- a/source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Environment/Environment.cpp
+++ b/source/tools/atlas/AtlasUI/ScenarioEditor/Sections/Environment/Environment.cpp
@@ -29,7 +29,9 @@ using AtlasMessage::Shareable;
 
 static Observable<AtlasMessage::sEnvironmentSettings> g_EnvironmentSettings;
 
+#ifndef M_PIf
 const float M_PIf = 3.14159265f;
+#endif
 
 //////////////////////////////////////////////////////////////////////////