diff --git a/src/Cargo.lock b/src/Cargo.lock
index c463f2bb747c..e7fa572fa3ad 100644
--- a/src/Cargo.lock
+++ b/src/Cargo.lock
@@ -221,6 +221,7 @@ dependencies = [
 name = "compiler_builtins"
 version = "0.0.0"
 dependencies = [
+ "build_helper 0.1.0",
  "core 0.0.0",
  "gcc 0.3.43 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
diff --git a/src/liballoc_jemalloc/build.rs b/src/liballoc_jemalloc/build.rs
index a3402bf39942..cd2e8e4ec20f 100644
--- a/src/liballoc_jemalloc/build.rs
+++ b/src/liballoc_jemalloc/build.rs
@@ -21,8 +21,6 @@ use std::process::Command;
 use build_helper::{run, rerun_if_changed_anything_in_dir, up_to_date};
 
 fn main() {
-    println!("cargo:rerun-if-changed=build.rs");
-
     // FIXME: This is a hack to support building targets that don't
     // support jemalloc alongside hosts that do. The jemalloc build is
     // controlled by a feature of the std crate, and if that feature
diff --git a/src/libcompiler_builtins/Cargo.toml b/src/libcompiler_builtins/Cargo.toml
index 1a549ae823ac..3f844b3f09e3 100644
--- a/src/libcompiler_builtins/Cargo.toml
+++ b/src/libcompiler_builtins/Cargo.toml
@@ -15,4 +15,5 @@ doc = false
 core = { path = "../libcore" }
 
 [build-dependencies]
+build_helper = { path = "../build_helper" }
 gcc = "0.3.27"
diff --git a/src/libcompiler_builtins/build.rs b/src/libcompiler_builtins/build.rs
index 16ecf8825667..564404ca71d6 100644
--- a/src/libcompiler_builtins/build.rs
+++ b/src/libcompiler_builtins/build.rs
@@ -33,6 +33,7 @@
 //! error (if any) and then we just add it to the list. Overall, that cost is
 //! far far less than working with compiler-rt's build system over time.
 
+extern crate build_helper;
 extern crate gcc;
 
 use std::collections::BTreeMap;
@@ -404,5 +405,8 @@ fn main() {
         cfg.file(Path::new("../compiler-rt/lib/builtins").join(src));
     }
 
+    // Can't reuse `sources` list becuse it doesn't contain header files.
+    build_helper::rerun_if_changed_anything_in_dir(Path::new("../compiler-rt"));
+
     cfg.compile("libcompiler-rt.a");
 }
diff --git a/src/libflate/build.rs b/src/libflate/build.rs
index 12016980a2c6..78d2ef1e37d2 100644
--- a/src/libflate/build.rs
+++ b/src/libflate/build.rs
@@ -11,6 +11,7 @@
 extern crate gcc;
 
 fn main() {
+    println!("cargo:rerun-if-changed=../rt/miniz.c");
     gcc::Config::new()
         .file("../rt/miniz.c")
         .compile("libminiz.a");
diff --git a/src/librustc_asan/build.rs b/src/librustc_asan/build.rs
index 015be14bd495..3e95e0dbebef 100644
--- a/src/librustc_asan/build.rs
+++ b/src/librustc_asan/build.rs
@@ -34,6 +34,4 @@ fn main() {
                 .unwrap())
             .join("../compiler-rt"));
     }
-
-    println!("cargo:rerun-if-changed=build.rs");
 }
diff --git a/src/librustc_llvm/build.rs b/src/librustc_llvm/build.rs
index c74a9308e4eb..b74bccb70593 100644
--- a/src/librustc_llvm/build.rs
+++ b/src/librustc_llvm/build.rs
@@ -144,9 +144,7 @@ fn main() {
         cfg.flag("-DLLVM_RUSTLLVM");
     }
 
-    println!("cargo:rerun-if-changed=../rustllvm/PassWrapper.cpp");
-    println!("cargo:rerun-if-changed=../rustllvm/RustWrapper.cpp");
-    println!("cargo:rerun-if-changed=../rustllvm/ArchiveWrapper.cpp");
+    build_helper::rerun_if_changed_anything_in_dir(Path::new("../rustllvm"));
     cfg.file("../rustllvm/PassWrapper.cpp")
        .file("../rustllvm/RustWrapper.cpp")
        .file("../rustllvm/ArchiveWrapper.cpp")
diff --git a/src/librustc_lsan/build.rs b/src/librustc_lsan/build.rs
index 5773777d1f81..ec968f51184f 100644
--- a/src/librustc_lsan/build.rs
+++ b/src/librustc_lsan/build.rs
@@ -34,6 +34,4 @@ fn main() {
                 .unwrap())
             .join("../compiler-rt"));
     }
-
-    println!("cargo:rerun-if-changed=build.rs");
 }
diff --git a/src/librustc_msan/build.rs b/src/librustc_msan/build.rs
index 7a4c8f707393..466fa641deab 100644
--- a/src/librustc_msan/build.rs
+++ b/src/librustc_msan/build.rs
@@ -34,6 +34,4 @@ fn main() {
                 .unwrap())
             .join("../compiler-rt"));
     }
-
-    println!("cargo:rerun-if-changed=build.rs");
 }
diff --git a/src/librustc_tsan/build.rs b/src/librustc_tsan/build.rs
index 84326ae8a710..95ce237b2673 100644
--- a/src/librustc_tsan/build.rs
+++ b/src/librustc_tsan/build.rs
@@ -34,6 +34,4 @@ fn main() {
                 .unwrap())
             .join("../compiler-rt"));
     }
-
-    println!("cargo:rerun-if-changed=build.rs");
 }
diff --git a/src/librustdoc/build.rs b/src/librustdoc/build.rs
index fcb7af11dce2..9fa6406c1d8b 100644
--- a/src/librustdoc/build.rs
+++ b/src/librustdoc/build.rs
@@ -8,9 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+extern crate build_helper;
 extern crate gcc;
 
 fn main() {
+    let src_dir = std::path::Path::new("../rt/hoedown/src");
+    build_helper::rerun_if_changed_anything_in_dir(src_dir);
     let mut cfg = gcc::Config::new();
     cfg.file("../rt/hoedown/src/autolink.c")
        .file("../rt/hoedown/src/buffer.c")
@@ -21,6 +24,6 @@ fn main() {
        .file("../rt/hoedown/src/html_smartypants.c")
        .file("../rt/hoedown/src/stack.c")
        .file("../rt/hoedown/src/version.c")
-       .include("../rt/hoedown/src")
+       .include(src_dir)
        .compile("libhoedown.a");
 }
diff --git a/src/libstd/build.rs b/src/libstd/build.rs
index 038dea77f3ea..834e3d092112 100644
--- a/src/libstd/build.rs
+++ b/src/libstd/build.rs
@@ -21,8 +21,6 @@ use std::process::Command;
 use build_helper::{run, rerun_if_changed_anything_in_dir, up_to_date};
 
 fn main() {
-    println!("cargo:rerun-if-changed=build.rs");
-
     let target = env::var("TARGET").expect("TARGET was not set");
     let host = env::var("HOST").expect("HOST was not set");
     if cfg!(feature = "backtrace") && !target.contains("apple") && !target.contains("msvc") &&
diff --git a/src/libunwind/build.rs b/src/libunwind/build.rs
index ea0d76978339..ed3d5212bf25 100644
--- a/src/libunwind/build.rs
+++ b/src/libunwind/build.rs
@@ -11,6 +11,7 @@
 use std::env;
 
 fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
     let target = env::var("TARGET").expect("TARGET was not set");
 
     if target.contains("linux") {