diff --git a/configure.py b/configure.py
index 8c021b9..2a5d3a7 100755
--- a/configure.py
+++ b/configure.py
@@ -86,6 +86,7 @@
 llvm_libdir = llvm_config(['--libdir'])
 
 llvm_clang = os.path.join(llvm_bindir, 'clang')
+llvm_as = os.path.join(llvm_bindir, 'llvm-as')
 llvm_link = os.path.join(llvm_bindir, 'llvm-link')
 llvm_opt = os.path.join(llvm_bindir, 'opt')
 
@@ -133,8 +134,7 @@
 
 b = metabuild.from_name(options.g)
 
-b.rule("LLVM_AS", "%s -o $out $in" % os.path.join(llvm_bindir, "llvm-as"),
-       'LLVM-AS $out')
+b.rule("LLVM_AS", "%s -o $out $in" % llvm_as, 'LLVM-AS $out')
 b.rule("LLVM_LINK", command = llvm_link + " -o $out $in",
        description = 'LLVM-LINK $out')
 b.rule("OPT", command = llvm_opt + " -O3 -o $out $in",