diff --git a/dart/utils/mjcf/detail/Compiler.cpp b/dart/utils/mjcf/detail/Compiler.cpp
index e4ad740d2ffe4..6d7cd014129e2 100644
--- a/dart/utils/mjcf/detail/Compiler.cpp
+++ b/dart/utils/mjcf/detail/Compiler.cpp
@@ -180,23 +180,11 @@ Errors Compiler::read(tinyxml2::XMLElement* element)
     const std::string inertiafromgeom
         = getAttributeString(element, "inertiafromgeom");
     if (inertiafromgeom == "false") {
-#if DART_OS_WINDOWS
       mInertiaFromGeom = InertiaFromGeom::IFG_FALSE;
-#else
-      mInertiaFromGeom = InertiaFromGeom::FALSE;
-#endif
     } else if (inertiafromgeom == "true") {
-#if DART_OS_WINDOWS
       mInertiaFromGeom = InertiaFromGeom::IFG_TRUE;
-#else
-      mInertiaFromGeom = InertiaFromGeom::TRUE;
-#endif
     } else if (inertiafromgeom == "auto") {
-#if DART_OS_WINDOWS
       mInertiaFromGeom = InertiaFromGeom::IFG_AUTO;
-#else
-      mInertiaFromGeom = InertiaFromGeom::AUTO;
-#endif
     } else {
       errors.emplace_back(
           ErrorCode::ATTRIBUTE_INVALID,
diff --git a/dart/utils/mjcf/detail/Compiler.hpp b/dart/utils/mjcf/detail/Compiler.hpp
index c858620f6e69e..2f50ea34db1ec 100644
--- a/dart/utils/mjcf/detail/Compiler.hpp
+++ b/dart/utils/mjcf/detail/Compiler.hpp
@@ -100,11 +100,7 @@ class Compiler final
   bool mConvexHull{true};
   bool mUserThread{true};
   bool mFuseStatic{false};
-#if DART_OS_WINDOWS
   InertiaFromGeom mInertiaFromGeom{InertiaFromGeom::IFG_AUTO};
-#else
-  InertiaFromGeom mInertiaFromGeom{InertiaFromGeom::AUTO};
-#endif
   Eigen::Vector2i mInertiaGroupRange{Eigen::Vector2i(0, 5)};
 };
 
diff --git a/dart/utils/mjcf/detail/Types.hpp b/dart/utils/mjcf/detail/Types.hpp
index 5c5f19bda16df..ebcfbfe4c79f1 100644
--- a/dart/utils/mjcf/detail/Types.hpp
+++ b/dart/utils/mjcf/detail/Types.hpp
@@ -77,15 +77,9 @@ enum class Integrator
 
 enum class InertiaFromGeom
 {
-#if DART_OS_WINDOWS
   IFG_FALSE,
   IFG_TRUE,
   IFG_AUTO,
-#else
-  FALSE,
-  TRUE,
-  AUTO,
-#endif
 };
 
 enum class CollisionType