diff --git a/sha2/Cargo.toml b/sha2/Cargo.toml
index b00cb4f..70ed1ec 100644
--- a/sha2/Cargo.toml
+++ b/sha2/Cargo.toml
@@ -11,7 +11,7 @@ categories = ["cryptography", "no-std"]
 edition = "2018"
 
 [dependencies]
-cpufeatures = "0.2.1"
+cpufeatures = "0.2"
 
 [build-dependencies]
 cc = "1.0"
diff --git a/sha2/src/lib.rs b/sha2/src/lib.rs
index 8fa3ccd..730e6c8 100644
--- a/sha2/src/lib.rs
+++ b/sha2/src/lib.rs
@@ -43,7 +43,7 @@ pub fn compress256(state: &mut [u32; 8], blocks: &[[u8; 64]]) {
 #[link(name = "sha512", kind = "static")]
 extern "C" {
     fn sha512_compress(state: &mut [u64; 8], block: &[u8; 128]);
-    fn sha512_transform_rorx(state: &mut [u64; 8], block: *const [u8; 128], num_blocks: u64);
+    fn sha512_transform_rorx(state: &mut [u64; 8], block: *const [u8; 128], num_blocks: usize);
 }
 
 /// Safe wrapper around assembly implementation of SHA512 compression function
@@ -55,7 +55,7 @@ pub fn compress512(state: &mut [u64; 8], blocks: &[[u8; 128]]) {
     let token: cpuid_avx2::InitToken = cpuid_avx2::init();
     if token.get() {
         if !blocks.is_empty() {
-            unsafe { sha512_transform_rorx(state, blocks.as_ptr(), blocks.len() as u64) }
+            unsafe { sha512_transform_rorx(state, blocks.as_ptr(), blocks.len()) }
         }
     } else {
         for block in blocks {