diff --git a/src/XMPPJID.m b/src/XMPPJID.m
index 1de2a04..7fca6af 100644
--- a/src/XMPPJID.m
+++ b/src/XMPPJID.m
@@ -58,18 +58,17 @@
 	if (nodesep == SIZE_MAX)
 		[self setNode: nil];
 	else
-		[self setNode: [str substringFromIndex: 0
-					       toIndex: nodesep]];
+		[self setNode: [str substringWithRange: of_range(0, nodesep)]];
 
 	if (resourcesep == SIZE_MAX) {
 		[self setResource: nil];
 		resourcesep = [str length];
 	} else
-		[self setResource: [str substringFromIndex: resourcesep + 1
-						 toIndex: [str length]]];
+		[self setResource: [str substringWithRange:
+		    of_range(resourcesep + 1, [str length] - resourcesep - 1)]];
 
-	[self setDomain: [str substringFromIndex: nodesep + 1
-					 toIndex: resourcesep]];
+	[self setDomain: [str substringWithRange:
+	    of_range(nodesep + 1, resourcesep - nodesep - 1)]];
 
 	return self;
 }
diff --git a/src/XMPPSCRAMAuth.m b/src/XMPPSCRAMAuth.m
index c5be21b..4811fe8 100644
--- a/src/XMPPSCRAMAuth.m
+++ b/src/XMPPSCRAMAuth.m
@@ -184,8 +184,8 @@
 	enumerator =
 	    [[chal componentsSeparatedByString: @","] objectEnumerator];
 	while ((comp = [enumerator nextObject]) != nil) {
-		OFString *entry = [comp substringFromIndex: 2
-						   toIndex: [comp length]];
+		OFString *entry = [comp substringWithRange:
+		    of_range(2, [comp length] - 2)];
 
 		if ([comp hasPrefix: @"r="]) {
 			if (![entry hasPrefix: cNonce])
@@ -333,8 +333,8 @@
 	OFString *mess = [OFString stringWithCString: [message cArray]
 					      length: [message count] *
 						      [message itemSize]];
-	OFString *value = [mess substringFromIndex: 2
-					   toIndex: [mess length]];
+	OFString *value = [mess substringWithRange:
+	    of_range(2, [mess length] - 2)];
 
 	if ([mess hasPrefix: @"v="]) {
 		if (![value isEqual: [serverSignature stringByBase64Encoding]])