diff --git a/Cargo.toml b/Cargo.toml
index 0f6b980..309ceea 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,4 +12,3 @@ edition = "2018"
 [dependencies]
 base64 = "0.10"
 chrono  = "0.4"
-http = "0.1.18"
diff --git a/src/create.rs b/src/create.rs
index 3ecf6d7..a212046 100644
--- a/src/create.rs
+++ b/src/create.rs
@@ -1,13 +1,10 @@
 use chrono::{DateTime, Utc};
-use http::header::{HeaderMap, HeaderName, HeaderValue, InvalidHeaderValue, AUTHORIZATION};
 
 use crate::{
     ALGORITHM_FIELD, ALGORITHM_VALUE, CREATED_FIELD, EXPIRES_FIELD, HEADERS_FIELD, KEY_ID_FIELD,
     SIGNATURE_FIELD,
 };
 
-const SIGNATURE_HEADER: &'static str = "Signature";
-
 pub struct Signed {
     signature: String,
     sig_headers: Vec<String>,
@@ -24,20 +21,12 @@ pub struct Unsigned {
 }
 
 impl Signed {
-    pub fn signature_header(self, hm: &mut HeaderMap) -> Result<(), InvalidHeaderValue> {
-        hm.insert(
-            AUTHORIZATION,
-            HeaderValue::from_str(&format!("Signature {}", self.into_header()))?,
-        );
-        Ok(())
+    pub fn signature_header(self) -> String {
+        format!("Signature {}", self.into_header())
     }
 
-    pub fn authorization_header(self, hm: &mut HeaderMap) -> Result<(), InvalidHeaderValue> {
-        hm.insert(
-            HeaderName::from_static(SIGNATURE_HEADER),
-            HeaderValue::from_str(&self.into_header())?,
-        );
-        Ok(())
+    pub fn authorization_header(self) -> String {
+        self.into_header()
     }
 
     fn into_header(self) -> String {
diff --git a/src/lib.rs b/src/lib.rs
index 7996a54..825fbf8 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,9 +1,4 @@
 use chrono::{DateTime, Duration, Utc};
-use http::{
-    header::{HeaderMap, ToStrError},
-    method::Method,
-    uri::PathAndQuery,
-};
 use std::collections::BTreeMap;
 
 pub mod create;
@@ -34,11 +29,11 @@ pub struct Config {
 impl Config {
     pub fn normalize(
         &self,
-        method: Method,
-        path_and_query: &PathAndQuery,
-        headers: &HeaderMap,
-    ) -> Result<Unsigned, ToStrError> {
-        let (sig_headers, mut btm) = build_headers_list(headers)?;
+        method: &str,
+        path_and_query: &str,
+        headers: &mut BTreeMap<String, String>,
+    ) -> Unsigned {
+        let sig_headers = build_headers_list(headers);
 
         let created = Utc::now();
         let expires = created + self.expires;
@@ -49,15 +44,15 @@ impl Config {
             Some(created),
             Some(expires),
             &sig_headers,
-            &mut btm,
+            headers,
         );
 
-        Ok(Unsigned {
+        Unsigned {
             signing_string,
             sig_headers,
             created,
             expires,
-        })
+        }
     }
 
     pub fn validate<F, T>(&self, unvalidated: Unvalidated, f: F) -> Result<T, ValidateError>
@@ -81,17 +76,7 @@ impl Config {
     }
 }
 
-fn build_headers_list(
-    headers: &HeaderMap,
-) -> Result<(Vec<String>, BTreeMap<String, String>), ToStrError> {
-    let btm: BTreeMap<String, String> = headers
-        .iter()
-        .map(|(k, v)| {
-            v.to_str()
-                .map(|v| (k.as_str().to_lowercase().to_owned(), v.to_owned()))
-        })
-        .collect::<Result<BTreeMap<String, String>, _>>()?;
-
+fn build_headers_list(btm: &BTreeMap<String, String>) -> Vec<String> {
     let http_header_keys: Vec<String> = btm.keys().cloned().collect();
 
     let mut sig_headers = vec![
@@ -102,12 +87,12 @@ fn build_headers_list(
 
     sig_headers.extend(http_header_keys);
 
-    Ok((sig_headers, btm))
+    sig_headers
 }
 
 fn build_signing_string(
-    method: Method,
-    path_and_query: &PathAndQuery,
+    method: &str,
+    path_and_query: &str,
     created: Option<DateTime<Utc>>,
     expires: Option<DateTime<Utc>>,
     sig_headers: &[String],
diff --git a/src/verify.rs b/src/verify.rs
index d5bd900..195d3a0 100644
--- a/src/verify.rs
+++ b/src/verify.rs
@@ -1,14 +1,14 @@
 use chrono::{DateTime, TimeZone, Utc};
-use http::{
-    header::{HeaderMap, ToStrError},
-    method::Method,
-    uri::PathAndQuery,
+use std::{
+    collections::{BTreeMap, HashMap},
+    error::Error,
+    fmt,
+    str::FromStr,
 };
-use std::{collections::HashMap, error::Error, fmt, str::FromStr};
 
 use crate::{
-    build_headers_list, build_signing_string, ALGORITHM_FIELD, CREATED, CREATED_FIELD,
-    EXPIRES_FIELD, HEADERS_FIELD, KEY_ID_FIELD, SIGNATURE_FIELD,
+    build_signing_string, ALGORITHM_FIELD, CREATED, CREATED_FIELD, EXPIRES_FIELD, HEADERS_FIELD,
+    KEY_ID_FIELD, SIGNATURE_FIELD,
 };
 
 pub struct Unvalidated {
@@ -76,22 +76,20 @@ impl Unvalidated {
 impl ParsedHeader {
     pub fn to_unvalidated(
         self,
-        method: Method,
-        path_and_query: &PathAndQuery,
-        headers: &HeaderMap,
-    ) -> Result<Unvalidated, ToStrError> {
-        let (_, mut btm) = build_headers_list(headers)?;
-
+        method: &str,
+        path_and_query: &str,
+        headers: &mut BTreeMap<String, String>,
+    ) -> Unvalidated {
         let signing_string = build_signing_string(
             method,
             path_and_query,
             self.created,
             self.expires,
             &self.headers,
-            &mut btm,
+            headers,
         );
 
-        Ok(Unvalidated {
+        Unvalidated {
             key_id: self.key_id,
             signature: self.signature,
             parsed_at: self.parsed_at,
@@ -99,7 +97,7 @@ impl ParsedHeader {
             created: self.created,
             expires: self.expires,
             signing_string,
-        })
+        }
     }
 }