diff --git a/src/user/CMakeLists.txt b/src/user/CMakeLists.txt
index 0727c5a9..a6914c9e 100644
--- a/src/user/CMakeLists.txt
+++ b/src/user/CMakeLists.txt
@@ -25,3 +25,4 @@ set(MUJOCO_USER_SRCS
 )
 
 target_sources(mujoco PRIVATE ${MUJOCO_USER_SRCS})
+target_compile_definitions(mujoco PRIVATE MUJOCO_TINYOBJLOADER_IMPL)
diff --git a/src/user/user_mesh.cc b/src/user/user_mesh.cc
index ed382f5c..0912bb12 100644
--- a/src/user/user_mesh.cc
+++ b/src/user/user_mesh.cc
@@ -22,7 +22,9 @@
 #include <string>
 #include <vector>
 
+#ifdef MUJOCO_TINYOBJLOADER_IMPL
 #define TINYOBJLOADER_IMPLEMENTATION
+#endif
 
 #include <mujoco/mjmodel.h>
 #include "cc/array_safety.h"