diff --git a/PySwiftyRegex.xcodeproj/project.pbxproj b/PySwiftyRegex.xcodeproj/project.pbxproj
index c9bf6c2..dcb55b6 100644
--- a/PySwiftyRegex.xcodeproj/project.pbxproj
+++ b/PySwiftyRegex.xcodeproj/project.pbxproj
@@ -280,7 +280,9 @@
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				INFOPLIST_FILE = PySwiftyRegex/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				MACH_O_TYPE = staticlib;
+				MACOSX_DEPLOYMENT_TARGET = 8.0;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = me.cezheng.PySwiftyRegex;
@@ -333,7 +335,9 @@
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				INFOPLIST_FILE = PySwiftyRegex/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				MACH_O_TYPE = staticlib;
+				MACOSX_DEPLOYMENT_TARGET = 8.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				PRODUCT_BUNDLE_IDENTIFIER = me.cezheng.PySwiftyRegex;
 				PRODUCT_NAME = "$(PROJECT_NAME)";
@@ -357,7 +361,7 @@
 				GCC_GENERATE_TEST_COVERAGE_FILES = YES;
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/Frameworks";
-				MACH_O_TYPE = mh_dylib;
+				MACH_O_TYPE = staticlib;
 				MACOSX_DEPLOYMENT_TARGET = 10.9;
 				SKIP_INSTALL = YES;
 				SWIFT_VERSION = 4.0;
@@ -376,7 +380,7 @@
 				GCC_GENERATE_TEST_COVERAGE_FILES = YES;
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/Frameworks";
-				MACH_O_TYPE = mh_dylib;
+				MACH_O_TYPE = staticlib;
 				MACOSX_DEPLOYMENT_TARGET = 10.9;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
diff --git a/PySwiftyRegex.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist b/PySwiftyRegex.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
new file mode 100644
index 0000000..18d9810
--- /dev/null
+++ b/PySwiftyRegex.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>
diff --git a/PySwiftyRegex/PySwiftyRegex.swift b/PySwiftyRegex/PySwiftyRegex.swift
index 6892c38..67dcb60 100644
--- a/PySwiftyRegex/PySwiftyRegex.swift
+++ b/PySwiftyRegex/PySwiftyRegex.swift
@@ -270,8 +270,7 @@ public class re {
         guard let result = result, result.range.length > 0 else {
           return
         }
-        
-        end = string.characters.index(string.startIndex, offsetBy: result.range.location)
+        end = string.index(string.startIndex, offsetBy: result.range.location)
         results.append(String(string[start..<end]))
         if regex.numberOfCaptureGroups > 0 {
           results += MatchObject(string: string, match: result).groups()
diff --git a/PySwiftyRegexTests/ReRegexObjectTests.swift b/PySwiftyRegexTests/ReRegexObjectTests.swift
index 65f18d7..fa6949f 100644
--- a/PySwiftyRegexTests/ReRegexObjectTests.swift
+++ b/PySwiftyRegexTests/ReRegexObjectTests.swift
@@ -33,9 +33,9 @@ class ReRegexObjectTests: XCTestCase {
     XCTAssertEqual(match.group()!, "this one is different from that")
     XCTAssertEqual(match.group(1)!, "this")
     XCTAssertEqual(match.group(2)!, "that")
-    XCTAssertEqual(match.span()!, string.startIndex..<string.characters.index(string.startIndex, offsetBy: 31))
-    XCTAssertEqual(match.span(1)!, string.startIndex..<string.characters.index(string.startIndex, offsetBy: 4))
-    XCTAssertEqual(match.span(2)!, string.characters.index(string.startIndex, offsetBy: 27)..<string.characters.index(string.startIndex, offsetBy: 31))
+    XCTAssertEqual(match.span()!, string.startIndex..<string.index(string.startIndex, offsetBy: 31))
+    XCTAssertEqual(match.span(1)!, string.startIndex..<string.index(string.startIndex, offsetBy: 4))
+    XCTAssertEqual(match.span(2)!, string.index(string.startIndex, offsetBy: 27)..<string.index(string.startIndex, offsetBy: 31))
   }
   
   func testMatchWithRangeSuccess() {
@@ -48,9 +48,9 @@ class ReRegexObjectTests: XCTestCase {
     XCTAssertEqual(match.group()!, "this one is different from that on")
     XCTAssertEqual(match.group(1)!, "this")
     XCTAssertEqual(match.group(2)!, "that")
-    XCTAssertEqual(match.span()!, string.characters.index(string.startIndex, offsetBy: 4)..<string.characters.index(string.startIndex, offsetBy: 38))
-    XCTAssertEqual(match.span(1)!, string.characters.index(string.startIndex, offsetBy: 4)..<string.characters.index(string.startIndex, offsetBy: 8))
-    XCTAssertEqual(match.span(2)!, string.characters.index(string.startIndex, offsetBy: 31)..<string.characters.index(string.startIndex, offsetBy: 35))
+    XCTAssertEqual(match.span()!, string.index(string.startIndex, offsetBy: 4)..<string.index(string.startIndex, offsetBy: 38))
+    XCTAssertEqual(match.span(1)!, string.index(string.startIndex, offsetBy: 4)..<string.index(string.startIndex, offsetBy: 8))
+    XCTAssertEqual(match.span(2)!, string.index(string.startIndex, offsetBy: 31)..<string.index(string.startIndex, offsetBy: 35))
   }
   
   func testMatchFailure() {
@@ -70,9 +70,9 @@ class ReRegexObjectTests: XCTestCase {
     XCTAssertEqual(match.group()!, "this one is different from that")
     XCTAssertEqual(match.group(1)!, "this")
     XCTAssertEqual(match.group(2)!, "that")
-    XCTAssertEqual(match.span()!, string.startIndex..<string.characters.index(string.startIndex, offsetBy: 31))
-    XCTAssertEqual(match.span(1)!, string.startIndex..<string.characters.index(string.startIndex, offsetBy: 4))
-    XCTAssertEqual(match.span(2)!, string.characters.index(string.startIndex, offsetBy: 27)..<string.characters.index(string.startIndex, offsetBy: 31))
+    XCTAssertEqual(match.span()!, string.startIndex..<string.index(string.startIndex, offsetBy: 31))
+    XCTAssertEqual(match.span(1)!, string.startIndex..<string.index(string.startIndex, offsetBy: 4))
+    XCTAssertEqual(match.span(2)!, string.index(string.startIndex, offsetBy: 27)..<string.index(string.startIndex, offsetBy: 31))
   }
   
   func testSearchWithRangeSuccess() {
@@ -85,9 +85,9 @@ class ReRegexObjectTests: XCTestCase {
     XCTAssertEqual(match.group()!, "this one is different from that on")
     XCTAssertEqual(match.group(1)!, "this")
     XCTAssertEqual(match.group(2)!, "that")
-    XCTAssertEqual(match.span()!, string.characters.index(string.startIndex, offsetBy: 4)..<string.characters.index(string.startIndex, offsetBy: 38))
-    XCTAssertEqual(match.span(1)!, string.characters.index(string.startIndex, offsetBy: 4)..<string.characters.index(string.startIndex, offsetBy: 8))
-    XCTAssertEqual(match.span(2)!, string.characters.index(string.startIndex, offsetBy: 31)..<string.characters.index(string.startIndex, offsetBy: 35))
+    XCTAssertEqual(match.span()!, string.index(string.startIndex, offsetBy: 4)..<string.index(string.startIndex, offsetBy: 38))
+    XCTAssertEqual(match.span(1)!, string.index(string.startIndex, offsetBy: 4)..<string.index(string.startIndex, offsetBy: 8))
+    XCTAssertEqual(match.span(2)!, string.index(string.startIndex, offsetBy: 31)..<string.index(string.startIndex, offsetBy: 35))
   }
   
   func testSearchNestGroupsSuccess() {
@@ -102,11 +102,11 @@ class ReRegexObjectTests: XCTestCase {
     XCTAssertEqual(match.group(2)!, "this ")
     XCTAssertEqual(match.group(3)!, " that that that ")
     XCTAssertEqual(match.group(4)!, "that ")
-    XCTAssertEqual(match.span()!, string.startIndex..<string.characters.index(string.startIndex, offsetBy: 52))
-    XCTAssertEqual(match.span(1)!, string.startIndex..<string.characters.index(string.startIndex, offsetBy: 15))
-    XCTAssertEqual(match.span(2)!, string.characters.index(string.startIndex, offsetBy: 10)..<string.characters.index(string.startIndex, offsetBy: 15))
-    XCTAssertEqual(match.span(3)!, string.characters.index(string.startIndex, offsetBy: 36)..<string.characters.index(string.startIndex, offsetBy: 52))
-    XCTAssertEqual(match.span(4)!, string.characters.index(string.startIndex, offsetBy: 47)..<string.characters.index(string.startIndex, offsetBy: 52))
+    XCTAssertEqual(match.span()!, string.startIndex..<string.index(string.startIndex, offsetBy: 52))
+    XCTAssertEqual(match.span(1)!, string.startIndex..<string.index(string.startIndex, offsetBy: 15))
+    XCTAssertEqual(match.span(2)!, string.index(string.startIndex, offsetBy: 10)..<string.index(string.startIndex, offsetBy: 15))
+    XCTAssertEqual(match.span(3)!, string.index(string.startIndex, offsetBy: 36)..<string.index(string.startIndex, offsetBy: 52))
+    XCTAssertEqual(match.span(4)!, string.index(string.startIndex, offsetBy: 47)..<string.index(string.startIndex, offsetBy: 52))
   }
   
   func testFindallSuccess() {