diff --git a/SwiftyRSA/PublicKey.swift b/SwiftyRSA/PublicKey.swift
index f2fea42..f2bca03 100644
--- a/SwiftyRSA/PublicKey.swift
+++ b/SwiftyRSA/PublicKey.swift
@@ -79,13 +79,13 @@ public class PublicKey: Key {
     public static func publicKeys(pemEncoded pemString: String) -> [PublicKey] {
         
         // If our regexp isn't valid, or the input string is empty, we can't move forward…
-        guard let publicKeyRegexp = publicKeyRegex, pemString.characters.count > 0 else {
+        guard let publicKeyRegexp = publicKeyRegex, pemString.count > 0 else {
             return []
         }
         
         let all = NSRange(
             location: 0,
-            length: pemString.characters.count
+            length: pemString.count
         )
         
         let matches = publicKeyRegexp.matches(
@@ -102,8 +102,8 @@ public class PublicKey: Key {
             let match = result.rangeAt(1)
             #endif
             
-            let start = pemString.characters.index(pemString.startIndex, offsetBy: match.location)
-            let end = pemString.characters.index(start, offsetBy: match.length)
+            let start = pemString.index(pemString.startIndex, offsetBy: match.location)
+            let end = pemString.index(start, offsetBy: match.length)
             
             let range = Range<String.Index>(start..<end)
             
diff --git a/SwiftyRSA/SwiftyRSA.swift b/SwiftyRSA/SwiftyRSA.swift
index b38d895..882f694 100644
--- a/SwiftyRSA/SwiftyRSA.swift
+++ b/SwiftyRSA/SwiftyRSA.swift
@@ -60,7 +60,7 @@ enum SwiftyRSA {
     static func format(keyData: Data, withPemType pemType: String) -> String {
         
         func split(_ str: String, byChunksOfLength length: Int) -> [String] {
-            return stride(from: 0, to: str.characters.count, by: length).map { index -> String in
+            return stride(from: 0, to: str.count, by: length).map { index -> String in
                 let startIndex = str.index(str.startIndex, offsetBy: index)
                 let endIndex = str.index(startIndex, offsetBy: length, limitedBy: str.endIndex) ?? str.endIndex
                 return String(str[startIndex..<endIndex])