diff --git a/lfs_util.h b/lfs_util.h
index dbb4c5b..fc1b0c2 100644
--- a/lfs_util.h
+++ b/lfs_util.h
@@ -49,6 +49,7 @@ extern "C"
 // code footprint
 
 // Logging functions
+#ifndef LFS_TRACE
 #ifdef LFS_YES_TRACE
 #define LFS_TRACE_(fmt, ...) \
     printf("%s:%d:trace: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -56,7 +57,9 @@ extern "C"
 #else
 #define LFS_TRACE(...)
 #endif
+#endif
 
+#ifndef LFS_DEBUG
 #ifndef LFS_NO_DEBUG
 #define LFS_DEBUG_(fmt, ...) \
     printf("%s:%d:debug: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -64,7 +67,9 @@ extern "C"
 #else
 #define LFS_DEBUG(...)
 #endif
+#endif
 
+#ifndef LFS_WARN
 #ifndef LFS_NO_WARN
 #define LFS_WARN_(fmt, ...) \
     printf("%s:%d:warn: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -72,7 +77,9 @@ extern "C"
 #else
 #define LFS_WARN(...)
 #endif
+#endif
 
+#ifndef LFS_ERROR
 #ifndef LFS_NO_ERROR
 #define LFS_ERROR_(fmt, ...) \
     printf("%s:%d:error: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -80,13 +87,16 @@ extern "C"
 #else
 #define LFS_ERROR(...)
 #endif
+#endif
 
 // Runtime assertions
+#ifndef LFS_ASSERT
 #ifndef LFS_NO_ASSERT
 #define LFS_ASSERT(test) assert(test)
 #else
 #define LFS_ASSERT(test)
 #endif
+#endif
 
 
 // Builtin functions, these may be replaced by more efficient