diff --git a/miniz_tdef.h b/miniz_tdef.h
index 6ce6938..f5d0daf 100644
--- a/miniz_tdef.h
+++ b/miniz_tdef.h
@@ -9,7 +9,9 @@ extern "C" {
 /* ------------------- Low-level Compression API Definitions */
 
 /* Set TDEFL_LESS_MEMORY to 1 to use less memory (compression will be slightly slower, and raw/dynamic blocks will be output more frequently). */
+#ifndef TDEFL_LESS_MEMORY
 #define TDEFL_LESS_MEMORY 0
+#endif
 
 /* tdefl_init() compression flags logically OR'd together (low 12 bits contain the max. number of probes per dictionary search): */
 /* TDEFL_DEFAULT_MAX_PROBES: The compressor defaults to 128 dictionary probes per dictionary search. 0=Huffman only, 1=Huffman+LZ (fastest/crap compression), 4095=Huffman+LZ (slowest/best compression). */