Index: src/OFNumber.m
==================================================================
--- src/OFNumber.m
+++ src/OFNumber.m
@@ -1389,11 +1389,21 @@
 	return [element autorelease];
 }
 
 - (OFString*)JSONRepresentation
 {
+	double doubleValue;
+
 	if (type == OF_NUMBER_BOOL)
 		return (value.bool_ ? @"true" : @"false");
+
+	doubleValue = [self doubleValue];
+	if (isinf(doubleValue)) {
+		if (doubleValue > 0)
+			return @"Infinity";
+		else
+			return @"-Infinity";
+	}
 
 	return [self description];
 }
 @end

Index: src/OFString+JSONValue.m
==================================================================
--- src/OFString+JSONValue.m
+++ src/OFString+JSONValue.m
@@ -16,10 +16,12 @@
 
 #include "config.h"
 
 #include <stdlib.h>
 #include <string.h>
+
+#include <math.h>
 
 #include <assert.h>
 
 #import "OFString+JSONValue.h"
 #import "OFArray.h"
@@ -560,10 +562,14 @@
 			number = [OFNumber numberWithDouble:
 			    [string doubleValue]];
 		else if (isHex)
 			number = [OFNumber numberWithIntMax:
 			    [string hexadecimalValue]];
+		else if ([string isEqual: @"Infinity"])
+			number = [OFNumber numberWithDouble: INFINITY];
+		else if ([string isEqual: @"-Infinity"])
+			number = [OFNumber numberWithDouble: -INFINITY];
 		else
 			number = [OFNumber numberWithIntMax:
 			    [string decimalValue]];
 	} @finally {
 		[string release];
@@ -627,12 +633,14 @@
 	case '5':
 	case '6':
 	case '7':
 	case '8':
 	case '9':
+	case '+':
 	case '-':
 	case '.':
+	case 'I':
 		return parseNumber(pointer, stop, line);
 	default:
 		return nil;
 	}
 }