diff --git a/build.rs b/build.rs
index a00752974..b23a7d3c0 100644
--- a/build.rs
+++ b/build.rs
@@ -8,7 +8,7 @@ use std::process::{Command, Stdio};
 fn main() {
     let out_dir = env::var("OUT_DIR").unwrap();
     let result = Command::new("make")
-        .args(&["-f", "makefile.cargo"])
+        .args(&["-R", "-f", "makefile.cargo"])
         .stdout(Stdio::inherit())
         .stderr(Stdio::inherit())
         .status()
diff --git a/makefile.cargo b/makefile.cargo
index 21c10fd8b..f2c74521f 100644
--- a/makefile.cargo
+++ b/makefile.cargo
@@ -1,7 +1,7 @@
 ifeq (eabi,$(findstring eabi,$(TARGET)))
 
-CXX := $(TARGET)-g++
-AR := $(TARGET)-ar
+CXX ?= $(TARGET)-g++
+AR ?= $(TARGET)-ar
 
 else