diff --git a/GNUmakefile b/GNUmakefile
index 8c452c1cc..f83de0ac5 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -71,10 +71,9 @@ else
 # Since C code is used only for supporting libraries (zlib, lua), it is still Ofast-optimized
 ################
 
-	CC_OPTIONS = -s -ggdb -g -D_DEBUG -O3
-
-CXX_OPTIONS = -s -ggdb -g -D_DEBUG -Og
-LNK_OPTIONS = -pthread -g -ggdb -Og
+CC_OPTIONS = -s -ggdb -g -D_DEBUG -O3
+CXX_OPTIONS = -s -ggdb -g -D_DEBUG -O1
+LNK_OPTIONS = -pthread -g -ggdb -O1
 BUILDDIR = build/debug/
 endif
 endif