diff --git a/Cargo.toml b/Cargo.toml
index 134abf26..b069e418 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,9 +17,9 @@ path       = "src/sdl2/lib.rs"
 
 [dependencies]
 bitflags = "0.7"
-libc = "0.2"
-rand = "0.3"
-lazy_static="0.2"
+libc = "^0.2"
+rand = "^0.5"
+lazy_static = "^1"
 
 [dependencies.num]
 version = "0.1"
diff --git a/sdl2-sys/Cargo.toml b/sdl2-sys/Cargo.toml
index a7cb9fb0..5e89a6fd 100644
--- a/sdl2-sys/Cargo.toml
+++ b/sdl2-sys/Cargo.toml
@@ -16,35 +16,35 @@ name = "sdl2_sys"
 path = "src/lib.rs"
 
 [build-dependencies.bindgen]
-version = "0.35"
+version = "^0.42"
 optional = true
 
 [build-dependencies.pkg-config]
-version = "0.3.9"
+version = "^0.3"
 optional = true
 
 [build-dependencies.cmake]
-version = "0.1"
+version = "^0.1"
 optional = true
 
 [build-dependencies.reqwest]
-version = "0.7"
+version = "^0.9"
 optional = true
 
 [build-dependencies.tar]
-version = "0.4"
+version = "^0.4"
 optional = true
 
 [build-dependencies.flate2]
-version = "0.2"
+version = "^1"
 optional = true
 
 [build-dependencies.unidiff]
-version = "0.2.1"
+version = "^0.2"
 optional = true
 
 [build-dependencies]
-cfg-if = "0.1"
+cfg-if = "^0.1"
 
 [features]
 
diff --git a/sdl2-sys/build.rs b/sdl2-sys/build.rs
index 38042e55..3931f254 100644
--- a/sdl2-sys/build.rs
+++ b/sdl2-sys/build.rs
@@ -43,9 +43,13 @@ fn download_to<T: io::Write>(url: &str, mut dest: T) {
     use io::BufRead;
 
     let resp = reqwest::get(url).expect(&format!("Failed to GET resource: {:?}", url));
-    let size = resp.headers()
-        .get::<reqwest::header::ContentLength>()
-        .map(|ct_len| **ct_len)
+    let size: u32 = resp.headers()
+        .get(reqwest::header::CONTENT_LENGTH)
+        .and_then(|cl| {
+            cl.to_str().ok().and_then(|cl| {
+                cl.parse::<u32>().ok()
+            })
+        })
         .unwrap_or(0);
     if !resp.status().is_success() { panic!("Download request failed with status: {:?}", resp.status()) }
     if size == 0 { panic!("Size of content was returned was 0") }
@@ -107,7 +111,7 @@ fn download_sdl2() -> PathBuf {
 
     let reader = flate2::read::GzDecoder::new(
         fs::File::open(&sdl2_archive_path).unwrap()
-    ).unwrap();
+    );
     let mut ar = tar::Archive::new(reader);
     ar.unpack(&out_dir).unwrap();