Index: src/OFConstantString.m
==================================================================
--- src/OFConstantString.m
+++ src/OFConstantString.m
@@ -547,10 +547,17 @@
 {
 	[self finishInitialization];
 
 	return [self hexadecimalValue];
 }
+
+- (uintmax_t)octalValue
+{
+	[self finishInitialization];
+
+	return [self octalValue];
+}
 
 - (float)floatValue
 {
 	[self finishInitialization];
 

Index: src/OFString.h
==================================================================
--- src/OFString.h
+++ src/OFString.h
@@ -950,38 +950,53 @@
  * @return The URL path with relative sub paths resolved
  */
 - (OFString*)stringByStandardizingURLPath;
 
 /*!
- * @brief Returns the decimal value of the string as an intmax_t.
+ * @brief Returns the decimal value of the string as an `intmax_t`.
  *
  * Leading and trailing whitespaces are ignored.
  *
  * If the string contains any non-number characters, an
- * OFInvalidEncodingException is thrown.
+ * @ref OFInvalidEncodingException is thrown.
  *
- * If the number is too big to fit into an intmax_t, an OFOutOfRangeException
- * is thrown.
+ * If the number is too big to fit into an `intmax_t`, an
+ * @ref OFOutOfRangeException is thrown.
  *
- * @return An intmax_t with the value of the string
+ * @return An `intmax_t` with the value of the string
  */
 - (intmax_t)decimalValue;
 
 /*!
- * @brief Returns the hexadecimal value of the string as an uintmax_t.
+ * @brief Returns the hexadecimal value of the string as an `uintmax_t`.
+ *
+ * Leading and trailing whitespaces are ignored.
+ *
+ * If the string contains any non-number characters, an
+ * @ref OFInvalidEncodingException is thrown.
+ *
+ * If the number is too big to fit into an `uintmax_t`, an
+ * @ref OFOutOfRangeException is thrown.
+ *
+ * @return A `uintmax_t` with the value of the string
+ */
+- (uintmax_t)hexadecimalValue;
+
+/*!
+ * @brief Returns the octal value of the string as an `uintmax_t`.
  *
  * Leading and trailing whitespaces are ignored.
  *
  * If the string contains any non-number characters, an
- * OFInvalidEncodingException is thrown.
+ * @ref OFInvalidEncodingException is thrown.
  *
- * If the number is too big to fit into an uintmax_t, an OFOutOfRangeException
- * is thrown.
+ * If the number is too big to fit into an `uintmax_t`, an
+ * @ref OFOutOfRangeException is thrown.
  *
- * @return A uintmax_t with the value of the string
+ * @return A `uintmax_t` with the value of the string
  */
-- (uintmax_t)hexadecimalValue;
+- (uintmax_t)octalValue;
 
 /*!
  * @brief Returns the float value of the string as a float.
  *
  * If the string contains any non-number characters, an

Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -2258,10 +2258,62 @@
 		value = newValue;
 	}
 
 	if (!foundValue)
 		@throw [OFInvalidFormatException exception];
+
+	objc_autoreleasePoolPop(pool);
+
+	return value;
+}
+
+- (uintmax_t)octalValue
+{
+	void *pool = objc_autoreleasePoolPush();
+	const of_unichar_t *characters = [self characters];
+	size_t i = 0, length = [self length];
+	uintmax_t value = 0;
+	bool expectWhitespace = false;
+
+	while (length > 0 && (*characters == ' ' || *characters == '\t' ||
+	    *characters == '\n' || *characters == '\r' ||
+	    *characters == '\f')) {
+		characters++;
+		length--;
+	}
+
+	if (length == 0) {
+		objc_autoreleasePoolPop(pool);
+		return 0;
+	}
+
+	for (; i < length; i++) {
+		uintmax_t newValue;
+
+		if (expectWhitespace) {
+			if (characters[i] != ' ' && characters[i] != '\t' &&
+			    characters[i] != '\n' && characters[i] != '\r' &&
+			    characters[i] != '\f')
+				@throw [OFInvalidFormatException exception];
+			continue;
+		}
+
+		if (characters[i] >= '0' && characters[i] <= '7')
+			newValue = (value << 3) | (characters[i] - '0');
+		else if (characters[i] == ' ' || characters[i] == '\t' ||
+		    characters[i] == '\n' || characters[i] == '\r' ||
+		    characters[i] == '\f') {
+			expectWhitespace = true;
+			continue;
+		} else
+			@throw [OFInvalidFormatException exception];
+
+		if (newValue < value)
+			@throw [OFOutOfRangeException exception];
+
+		value = newValue;
+	}
 
 	objc_autoreleasePoolPop(pool);
 
 	return value;
 }

Index: tests/OFStringTests.m
==================================================================
--- tests/OFStringTests.m
+++ tests/OFStringTests.m
@@ -442,10 +442,16 @@
 	    [@"  xbCDE" hexadecimalValue] == 0xBCDE &&
 	    [@"$CdEf" hexadecimalValue] == 0xCDEF &&
 	    [@"\rFeh " hexadecimalValue] == 0xFE &&
 	    [@"\r\t" hexadecimalValue] == 0)
 
+	TEST(@"-[octalValue]",
+	    [@"1234567" octalValue] == 01234567 &&
+	    [@"\r\n123" octalValue] == 0123 &&
+	    [@"765\t" octalValue] == 0765 &&
+	    [@"\t\t\r\n" octalValue] == 0)
+
 	/*
 	 * These test numbers can be generated without rounding if we have IEEE
 	 * floating point numbers, thus we can use == on them.
 	 */
 	TEST(@"-[floatValue]",