diff --git a/AppKit/CPFont.j b/AppKit/CPFont.j
index 28e4b7527..16b34d42c 100644
--- a/AppKit/CPFont.j
+++ b/AppKit/CPFont.j
@@ -28,8 +28,10 @@
 CPFontDefaultSystemFontFace = @"Arial, sans-serif";
 CPFontDefaultSystemFontSize = 12;
 
-// To create a font of a size that will always reflect the current
-// system font size, use this for the size argument.
+/*!
+    To create a font of a size that will dynamically reflect the current
+    system font size, use this for the size argument.
+*/
 CPFontCurrentSystemSize = -1;
 
 // For internal use only by this class and subclasses
@@ -43,7 +45,7 @@ var _CPFontCache                     = {},
     _CPFontStripRegExp               = new RegExp("(^\\s*[\"']?|[\"']?\\s*$)", "g");
 
 
-#define _CPRealFontSize(aSize)  (aSize === CPFontCurrentSystemSize ? _CPFontSystemFontSize : aSize)
+#define _CPRealFontSize(aSize)  (aSize <= 0 ? _CPFontSystemFontSize : aSize)
 #define _CPFontNormalizedNames(aName)  _CPFontNormalizedNameArray(aName).join(", ")
 #define _CPCachedFont(aName, aSize, isBold, isItalic)  _CPFontCache[_CPFontCreateCSSString(_CPFontNormalizedNames(aName), aSize, isBold, isItalic)]
 #define _CPUserFont(aName, aSize, isBold, isItalic)  _CPCachedFont(aName, aSize, isBold, isItalic) || [[CPFont alloc] _initWithName:aName size:aSize bold:isBold italic:isItalic system:NO]
@@ -202,67 +204,75 @@ following:
 /*!
     Returns a font with the specified name and size.
     @param aName the name of the font
-    @param aSize the size of the font (in px)
+    @param aSize the size of the font (in px). 0 or negative will create a font
+           in the current system font size.
     @return the requested font
 */
 + (CPFont)fontWithName:(CPString)aName size:(float)aSize
 {
-    return _CPUserFont(aName, aSize, NO, NO);
+    return _CPUserFont(aName, aSize <= 0 ? _CPFontSystemFontSize : aSize, NO, NO);
 }
 
 /*!
     Returns a font with the specified name, size and style.
     @param aName the name of the font
-    @param aSize the size of the font (in px)
+    @param aSize the size of the font (in px). 0 or negative will create a font
+           in the current system font size.
     @param italic whether the font should be italicized
     @return the requested font
 */
 + (CPFont)fontWithName:(CPString)aName size:(float)aSize italic:(BOOL)italic
 {
-    return _CPUserFont(aName, aSize, NO, italic);
+    return _CPUserFont(aName, aSize <= 0 ? _CPFontSystemFontSize : aSize, NO, italic);
 }
 
 /*!
     Returns a bold font with the specified name and size.
     @param aName the name of the font
-    @param aSize the size of the font (in px)
+    @param aSize the size of the font (in px). 0 or negative will create a font
+           in the current system font size.
     @return the requested bold font
 */
 + (CPFont)boldFontWithName:(CPString)aName size:(float)aSize
 {
-    return _CPUserFont(aName, aSize, YES, NO);
+    return _CPUserFont(aName, aSize <= 0 ? _CPFontSystemFontSize : aSize, YES, NO);
 }
 
 /*!
     Returns a bold font with the specified name, size and style.
     @param aName the name of the font
-    @param aSize the size of the font (in px)
+    @param aSize the size of the font (in px). 0 or negative will create a font
+           in the current system font size.
     @param italic whether the font should be italicized
     @return the requested font
 */
 + (CPFont)boldFontWithName:(CPString)aName size:(float)aSize italic:(BOOL)italic
 {
-    return _CPUserFont(aName, aSize, YES, italic);
+    return _CPUserFont(aName, aSize <= 0 ? _CPFontSystemFontSize : aSize, YES, italic);
 }
 
 /*!
     Returns the system font scaled to the specified size
-    @param aSize the size of the font (in px)
+    @param aSize the size of the font (in px). 0 creates a static font
+           in the current system font size. Negative creates a font
+           that dynamically tracks the current system font size.
     @return the requested system font
 */
 + (CPFont)systemFontOfSize:(CPSize)aSize
 {
-    return _CPSystemFont(aSize, NO);
+    return _CPSystemFont(aSize === 0 ? _CPFontSystemFontSize : aSize, NO);
 }
 
 /*!
     Returns the bold system font scaled to the specified size
-    @param aSize the size of the font (in px)
+    @param aSize the size of the font (in px). 0 creates a static font
+           in the current system font size. Negative creates a font
+           that dynamically tracks the current system font size.
     @return the requested bold system font
 */
 + (CPFont)boldSystemFontOfSize:(CPSize)aSize
 {
-    return _CPSystemFont(aSize, YES);
+    return _CPSystemFont(aSize === 0 ? _CPFontSystemFontSize : aSize, YES);
 }
 
 - (id)_initWithName:(CPString)aName size:(float)aSize bold:(BOOL)isBold italic:(BOOL)isItalic system:(BOOL)isSystem
@@ -369,7 +379,7 @@ following:
 
 - (BOOL)isSystemSize
 {
-    return _size === CPFontCurrentSystemSize;
+    return _size <= 0;
 }
 
 - (BOOL)isEqual:(id)anObject
diff --git a/Tests/AppKit/CPFontTest.j b/Tests/AppKit/CPFontTest.j
index c1ce8c887..77a51ff09 100644
--- a/Tests/AppKit/CPFontTest.j
+++ b/Tests/AppKit/CPFontTest.j
@@ -68,22 +68,59 @@
     {
         [inv setArgument:arg atIndex:idx + 2];
     }];
-    
+
     [inv invoke];
     var font = [inv returnValue];
-    
+
     [self assertTrue:([font isBold] == bold) message: [font description] + " should be bold: " + bold];
     [self assertTrue:([font isItalic] == italic) message: [font description] + " should be italic: " + italic];
-    
+
     // get from cache
     [inv invoke];
     var cachedFont = [inv returnValue];
     [self assert:cachedFont equals:font];
-    
+
     [self assertTrue:([cachedFont isBold] == bold) message:" cached " + [cachedFont description] + " should be bold: " + bold];
     [self assertTrue:([cachedFont isItalic] == italic) message:" cached " + [cachedFont description] + " should be italic: " + italic];
 }
 
+- (void)testSizes
+{
+    var font = [CPFont fontWithName:@"Arial" size:0],
+        systemSize = [CPFont systemFontSize];
+
+    [self assertTrue:([font size] === systemSize) message:" font size should be system size (" + systemSize + ")"];
+
+    var sysfont1 = [CPFont systemFontOfSize:12];
+    [self assertTrue:([sysfont1 size] === 12) message:" font size should be 12"];
+
+    var sysfont2 = [CPFont systemFontOfSize:0];
+    [self assertTrue:([sysfont2 size] === systemSize) message:" font size should be system size (" + systemSize + ")"];
+
+    var sysfont3 = [CPFont systemFontOfSize:-1];
+    [self assertTrue:([sysfont3 size] === systemSize) message:" font size should be system size (" + systemSize + ")"];
+
+    var newSystemSize = 13;
+    [CPFont setSystemFontSize:newSystemSize];
+    [self assertTrue:([sysfont2 size] === systemSize) message:" font size should be old system size (" + systemSize + ")"];
+    [self assertTrue:([sysfont3 size] === newSystemSize) message:" font size should be new system size (" + newSystemSize + ")"];
+}
+
+- (void)testFaces
+{
+    var font = [CPFont fontWithName:@"Georgia" size:0],
+        systemFace = [CPFont systemFontFace];
+
+    [self assertTrue:([font familyName] === @"Georgia") message:" font face should be Georgia"];
+
+    var sysfont = [CPFont systemFontOfSize:12];
+    [self assertTrue:([sysfont familyName] === systemFace) message:" font face should be system face (" + systemFace + ")"];
+
+    var newSystemFace = @"Georgia";
+    [CPFont setSystemFontFace:newSystemFace];
+    [self assertTrue:([sysfont familyName] === newSystemFace) message:" font face should be new system face (" + newSystemFace + ")"];
+}
+
 @end
 
 var _CPFontStripRegExp = new RegExp("(^\\s*[\"']?|[\"']?\\s*$)", "g");