diff --git a/services/crypto/Makefile b/services/crypto/Makefile
index 9d440ae2014..93b2ec9bff3 100755
--- a/services/crypto/Makefile
+++ b/services/crypto/Makefile
@@ -275,7 +275,6 @@ clean:
           $(cpp_objects) $(cpp_objects_i386) $(cpp_objects_ppc) \
           $(idl_typelib) $(idl_headers) $(target:=.res) fake.lib fake.exp WeaveCrypto.rc
 
-substitute = perl -p -e 's/@([^@]+)@/defined $$ENV{$$1} ? $$ENV{$$1} : $$&/ge'
 subst:
 	$(substitute) WeaveCrypto.rc.in > WeaveCrypto.rc