Index: Makefile
--- Makefile.orig
+++ Makefile
@@ -41,10 +41,10 @@ else
 ifdef USE_SGICC
 CC := cc
 else
-CC := gcc
+CC ?= gcc
 endif
 endif
-AR := ar
+AR ?= ar
 
 
 # Configuration.
@@ -226,13 +226,13 @@ DBGFLAGS := -n32 -g3 -DDEBUGMODE=1
 else
 WFLAGS := -Wall -W -Wwrite-strings -Wstrict-prototypes -Wmissing-declarations -DDUMB_DECLARE_DEPRECATED
 WFLAGS_ALLEGRO := -Wno-missing-declarations
-OFLAGS := -O2 -ffast-math -fomit-frame-pointer
-DBGFLAGS := -DDEBUGMODE=1 -g3
+OFLAGS := -O2 -ffast-math -fomit-frame-pointer -fgnu89-inline
+DBGFLAGS := -DDEBUGMODE=1 -g3 -fgnu89-inline
 endif
 endif
 
-CFLAGS_RELEASE := -Iinclude $(WFLAGS) $(OFLAGS)
-CFLAGS_DEBUG := -Iinclude $(WFLAGS) $(DBGFLAGS)
+CFLAGS_RELEASE := -Iinclude ${CFLAGS} $(WFLAGS) $(OFLAGS)
+CFLAGS_DEBUG := -Iinclude ${CFLAGS} $(WFLAGS) $(DBGFLAGS)
 
 LDFLAGS := -s