Index: src/OFConstantString.m
==================================================================
--- src/OFConstantString.m
+++ src/OFConstantString.m
@@ -481,11 +481,11 @@
 {
 	[self finishInitialization];
 	return self.longLongValue;
 }
 
-- (long long)longLongValueWithBase: (int)base
+- (long long)longLongValueWithBase: (unsigned char)base
 {
 	[self finishInitialization];
 	return [self longLongValueWithBase: base];
 }
 
@@ -493,11 +493,11 @@
 {
 	[self finishInitialization];
 	return self.unsignedLongLongValue;
 }
 
-- (unsigned long long)unsignedLongLongValueWithBase: (int)base
+- (unsigned long long)unsignedLongLongValueWithBase: (unsigned char)base
 {
 	[self finishInitialization];
 	return [self unsignedLongLongValueWithBase: base];
 }
 

Index: src/OFString.h
==================================================================
--- src/OFString.h
+++ src/OFString.h
@@ -1044,11 +1044,11 @@
  * 	       string starts with 0x (after stripping white spaces). If the
  * 	       string starts with 0, base 8 is assumed. Otherwise, base 10 is
  * 	       assumed.
  * @return The value of the string in the specified base
  */
-- (long long)longLongValueWithBase: (int)base;
+- (long long)longLongValueWithBase: (unsigned char)base;
 
 /**
  * @brief The value of the string in the specified base as an
  *	  `unsigned long long`.
  *
@@ -1064,11 +1064,11 @@
  * 	       string starts with 0x (after stripping white spaces). If the
  * 	       string starts with 0, base 8 is assumed. Otherwise, base 10 is
  * 	       assumed.
  * @return The value of the string in the specified base
  */
-- (unsigned long long)unsignedLongLongValueWithBase: (int)base;
+- (unsigned long long)unsignedLongLongValueWithBase: (unsigned char)base;
 
 /**
  * @brief Creates a new string by appending another string.
  *
  * @param string The string to append

Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -2290,11 +2290,11 @@
 - (long long)longLongValue
 {
 	return [self longLongValueWithBase: 10];
 }
 
-- (long long)longLongValueWithBase: (int)base
+- (long long)longLongValueWithBase: (unsigned char)base
 {
 	void *pool = objc_autoreleasePoolPush();
 	const char *UTF8String = self.UTF8String;
 	bool negative = false;
 	long long value = 0;
@@ -2366,11 +2366,11 @@
 - (unsigned long long)unsignedLongLongValue
 {
 	return [self unsignedLongLongValueWithBase: 10];
 }
 
-- (unsigned long long)unsignedLongLongValueWithBase: (int)base
+- (unsigned long long)unsignedLongLongValueWithBase: (unsigned char)base
 {
 	void *pool = objc_autoreleasePoolPush();
 	const char *UTF8String = self.UTF8String;
 	unsigned long long value = 0;
 

Index: src/OFXMLNode.h
==================================================================
--- src/OFXMLNode.h
+++ src/OFXMLNode.h
@@ -97,11 +97,11 @@
  * 	       string starts with 0, base 8 is assumed. Otherwise, base 10 is
  * 	       assumed.
  * @return The contents of the receiver as a `long long` value in the specified
  *	   base
  */
-- (long long)longLongValueWithBase: (int)base;
+- (long long)longLongValueWithBase: (unsigned char)base;
 
 /**
  * @brief The contents of the receiver as an `unsigned long long` value in the
  *	  specified base.
  *
@@ -110,9 +110,9 @@
  * 	       string starts with 0, base 8 is assumed. Otherwise, base 10 is
  * 	       assumed.
  * @return The contents of the receiver as an `unsigned long long` value in the
  * 	   specified base
  */
-- (unsigned long long)unsignedLongLongValueWithBase: (int)base;
+- (unsigned long long)unsignedLongLongValueWithBase: (unsigned char)base;
 @end
 
 OF_ASSUME_NONNULL_END

Index: src/OFXMLNode.m
==================================================================
--- src/OFXMLNode.m
+++ src/OFXMLNode.m
@@ -47,21 +47,21 @@
 - (long long)longLongValue
 {
 	return self.stringValue.longLongValue;
 }
 
-- (long long)longLongValueWithBase: (int)base
+- (long long)longLongValueWithBase: (unsigned char)base
 {
 	return [self.stringValue longLongValueWithBase: base];
 }
 
 - (unsigned long long)unsignedLongLongValue
 {
 	return self.stringValue.unsignedLongLongValue;
 }
 
-- (unsigned long long)unsignedLongLongValueWithBase: (int)base
+- (unsigned long long)unsignedLongLongValueWithBase: (unsigned char)base
 {
 	return [self.stringValue unsignedLongLongValueWithBase: base];
 }
 
 - (float)floatValue