diff --git a/Makefile.linux b/Makefile.linux
index 4b26b22e9d..5a47d9836d 100644
--- a/Makefile.linux
+++ b/Makefile.linux
@@ -2,14 +2,14 @@
 CXX ?= g++
 CC ?= gcc
 NASM ?= nasm
-ifndef DEBUG
-	ifndef NOGC
-		CFLAGS ?= -pipe -Wall -Wno-unused -O2 -fomit-frame-pointer -ffunction-sections -fvtable-gc -fno-rtti
-	else
-		CFLAGS ?= -pipe -Wall -Wno-unused -O2 -fomit-frame-pointer -ffunction-sections -fno-rtti
-	endif
+ifdef DEBUG
+  CFLAGS ?= -pipe -Wall -Wno-unused
 else
-	CFLAGS ?= -pipe -Wall -Wno-unused
+  CFLAGS ?= -pipe -Wall -Wno-unused -O2 -fomit-frame-pointer -fno-rtti
+endif
+ifdef GC
+  CFLAGS += -ffunction-sections
+  LDFLAGS += -Wl,--gc-sections
 endif
 CFLAGS += -DHAVE_FILELENGTH -D__forceinline=inline -Izlib -IFLAC `sdl-config --cflags`
 CFLAGS += -Dstricmp=strcasecmp -Dstrnicmp=strncasecmp -DNEED_STRUPR
@@ -25,11 +25,11 @@ DEBUGOBJ ?= debugobj
 
 CPPSRCS = $(wildcard $(addsuffix *.cpp,$(SRCDIRS)))
 CSRCS = $(wildcard $(addsuffix *.c,$(SRCDIRS)))
-ifndef NOASM
+ifdef NOASM
+  CFLAGS += -DNOASM
+else
   ASRCS = $(wildcard src/*.nas)
   CFLAGS += -DUSEASM=1
-else
-  CFLAGS += -DNOASM
 endif
 SRCS = $(CSRCS) $(CPPSRCS) $(ASRCS)
 CPPOBJFILES = $(notdir $(patsubst %.cpp,%.o,$(CPPSRCS)))
@@ -39,20 +39,16 @@ AOBJFILES = $(notdir $(patsubst %.nas,%.o,$(ASRCS)))
 ZDOOM = zdoom
 ZDOOMDEBUG = zdoomd
 
-ifndef DEBUG
-  OBJDIR = $(RELEASEOBJ)
-  CFLAGS += -DNDEBUG
-	ifndef NOGC
-	  LDFLAGS += -s -Wl,--gc-sections,-Map=$(ZDOOM).map
-	else
-		LDFLAGS += -s -Wl,-Map=$(ZDOOM).map
-	endif
-  ZDOOMBIN = $(ZDOOM)
-else
+ifdef DEBUG
   OBJDIR = $(DEBUGOBJ)
   CFLAGS += -D_DEBUG -g3
   NASMFLAGS += -g
   ZDOOMBIN = $(ZDOOMDEBUG)
+else
+  OBJDIR = $(RELEASEOBJ)
+  CFLAGS += -DNDEBUG
+  LDFLAGS += -s -Wl,-Map=$(ZDOOM).map
+  ZDOOMBIN = $(ZDOOM)
 endif
 CXXFLAGS += $(CFLAGS)
 
diff --git a/default.cbd b/default.cbd
index f89ef8605a..c1b8d18d3f 100644
--- a/default.cbd
+++ b/default.cbd
@@ -52,10 +52,16 @@ do ifopt debug
   TARGET = "${DEBUGTARGET}"
 else
   OBJDIR = "${RELEASEOBJDIR}"
-  CFLAGS += "-march=${ARCH_TYPE} -mtune=${TUNE_TYPE} -Wall -Wno-unused -O${OPTLEVEL} -fomit-frame-pointer -ffunction-sections -fvtable-gc -fno-rtti"
+  CFLAGS += "-march=${ARCH_TYPE} -mtune=${TUNE_TYPE} -Wall -Wno-unused -O${OPTLEVEL} -fomit-frame-pointer -ffunction-sections -fno-rtti"
+  ifopt gc
+    CFLAGS += "-march=${ARCH_TYPE} -mtune=${TUNE_TYPE} -Wall -Wno-unused -O${OPTLEL} -fomit-frame-pointer -fno-rtti"
+  done
   CPPFLAGS += " -DNDEBUG"
   CXXFLAGS = "${CFLAGS}"
-  LDFLAGS += " -s -Wl,--gc-sections,-Map=zdoomgcc.map"
+  LDFLAGS += " -s -Wl,-Map=zdoomgcc.map"
+  ifopt gc
+    LDFLAGS += " -Wl,--gc-sections"
+  done
   TARGET = "${RELEASETARGET}"
 done
 
@@ -457,7 +463,7 @@ ${COMPILER} xlat-parse.tab.c gen.c
 ${LINK} tools/xlatcc/xlatcc
 
 src_paths  tools/dehsupp
-${COMPILER} parse.tab.c
+${COMPILER} parse.c scanner.c dehsupp.c
 ${LINK} tools/dehsupp/dehsupp
 
 do if "${EVILCLEAN}"="1"