diff --git a/config/optimize b/config/optimize
index 5256dc7b58..6122fc54a9 100644
--- a/config/optimize
+++ b/config/optimize
@@ -40,11 +40,11 @@ CXXFLAGS_OPTIM_SPEED="$CFLAGS_OPTIM_SPEED"
 CFLAGS_OPTIM_SIZE="-Os -fomit-frame-pointer -DNDEBUG"
 CXXFLAGS_OPTIM_SIZE="$CFLAGS_OPTIM_SIZE"
 # debug settings
-CFLAGS_OPTIM_DEBUG="-ggdb -Os"
+CFLAGS_OPTIM_DEBUG="-ggdb -Og"
 CXXFLAGS_OPTIM_DEBUG="$CFLAGS_OPTIM_DEBUG"
 LDFLAGS_OPTIM_DEBUG="-ggdb"
 # split debug settings (requires gold)
-CFLAGS_OPTIM_DEBUG_SPLIT="-gsplit-dwarf -Os"
+CFLAGS_OPTIM_DEBUG_SPLIT="-gsplit-dwarf -Og"
 CXXFLAGS_OPTIM_DEBUG_SPLIT="$CFLAGS_OPTIM_DEBUG_SPLIT"
 LDFLAGS_OPTIM_DEBUG_SPLIT="-Wl,--gdb-index"