diff --git a/Makefile b/Makefile
index 33bfb0a..af625c8 100644
--- a/Makefile
+++ b/Makefile
@@ -29,10 +29,10 @@ OBJS = \
        vm.o\
 
 # Cross-compiling (e.g., on Mac OS X)
-#TOOLPREFIX = i386-jos-elf-
+TOOLPREFIX = /opt/gnu/bin/i386-jos-elf-
 
 # Using native tools (e.g., on X86 Linux)
-#TOOLPREFIX = 
+#TOOLPREFIX =
 
 # Try to infer the correct TOOLPREFIX if not set
 ifndef TOOLPREFIX
@@ -51,7 +51,7 @@ TOOLPREFIX := $(shell if i386-jos-elf-objdump -i 2>&1 | grep '^elf32-i386$$' >/d
 endif
 
 # If the makefile can't find QEMU, specify its path here
-#QEMU = 
+QEMU = qemu-system-i386
 
 # Try to infer the correct QEMU
 ifndef QEMU
@@ -67,8 +67,8 @@ QEMU = $(shell if which qemu > /dev/null; \
        echo "***" 1>&2; exit 1)
 endif
 
-CC = $(TOOLPREFIX)gcc
-AS = $(TOOLPREFIX)gas
+CC = /opt/gnu/gcc
+AS = $(TOOLPREFIX)as
 LD = $(TOOLPREFIX)ld
 OBJCOPY = $(TOOLPREFIX)objcopy
 OBJDUMP = $(TOOLPREFIX)objdump