diff --git a/HTMLKit.xcodeproj/project.pbxproj b/HTMLKit.xcodeproj/project.pbxproj
index 3c66070..551319f 100644
--- a/HTMLKit.xcodeproj/project.pbxproj
+++ b/HTMLKit.xcodeproj/project.pbxproj
@@ -2128,8 +2128,10 @@
 				FRAMEWORK_VERSION = A;
 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
 				GCC_PREFIX_HEADER = "";
+				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_INCOMPATIBLE_POINTER_TYPE_WARNINGS_AS_ERRORS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
+				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
 				INFOPLIST_FILE = "Sources/HTMLKit-Info.plist";
 				INSTALL_PATH = "@rpath";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
@@ -2154,8 +2156,10 @@
 				FRAMEWORK_VERSION = A;
 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
 				GCC_PREFIX_HEADER = "";
+				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_INCOMPATIBLE_POINTER_TYPE_WARNINGS_AS_ERRORS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
+				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
 				INFOPLIST_FILE = "Sources/HTMLKit-Info.plist";
 				INSTALL_PATH = "@rpath";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
@@ -2232,7 +2236,9 @@
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_PREFIX_HEADER = "";
+				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
+				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
 				INFOPLIST_FILE = "Sources/HTMLKit-Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
@@ -2268,7 +2274,9 @@
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_PREFIX_HEADER = "";
+				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
+				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
 				INFOPLIST_FILE = "Sources/HTMLKit-Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
@@ -2306,7 +2314,9 @@
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_PREFIX_HEADER = "";
+				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
+				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
 				INFOPLIST_FILE = "Sources/HTMLKit-Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
@@ -2342,7 +2352,9 @@
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_PREFIX_HEADER = "";
+				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
+				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
 				INFOPLIST_FILE = "Sources/HTMLKit-Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
@@ -2418,8 +2430,10 @@
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_PREFIX_HEADER = "";
+				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_INCOMPATIBLE_POINTER_TYPE_WARNINGS_AS_ERRORS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
+				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
 				GCC_WARN_INHIBIT_ALL_WARNINGS = NO;
 				GCC_WARN_PEDANTIC = NO;
 				INFOPLIST_FILE = "Sources/HTMLKit-Info.plist";
@@ -2455,8 +2469,10 @@
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_PREFIX_HEADER = "";
+				GCC_TREAT_IMPLICIT_FUNCTION_DECLARATIONS_AS_ERRORS = YES;
 				GCC_TREAT_INCOMPATIBLE_POINTER_TYPE_WARNINGS_AS_ERRORS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
+				GCC_WARN_ABOUT_MISSING_PROTOTYPES = YES;
 				GCC_WARN_INHIBIT_ALL_WARNINGS = NO;
 				GCC_WARN_PEDANTIC = NO;
 				INFOPLIST_FILE = "Sources/HTMLKit-Info.plist";
diff --git a/Sources/CSSNthExpressionSelector.m b/Sources/CSSNthExpressionSelector.m
index 9f74f8b..d93f918 100644
--- a/Sources/CSSNthExpressionSelector.m
+++ b/Sources/CSSNthExpressionSelector.m
@@ -38,7 +38,7 @@ NSString * _Nonnull NSStringFromNthExpression(CSSNthExpression expression)
 
 #pragma mark - Implementation
 
-NSInteger computeIndex(NSEnumerator *enumerator, HTMLElement *element)
+NS_INLINE NSInteger computeIndex(NSEnumerator *enumerator, HTMLElement *element)
 {
 	NSInteger index = 0;
 	for (HTMLNode *node in enumerator) {