diff --git a/Languages/Smalltalk/NSString+additions.h b/Languages/Smalltalk/NSString+additions.h
new file mode 100644
index 0000000..61a6e64
--- /dev/null
+++ b/Languages/Smalltalk/NSString+additions.h
@@ -0,0 +1,32 @@
+/**
+    NSString-additions.h
+    Various methods for NSString
+ 
+    Copyright (c) 2002 Free Software Foundation
+ 
+    Date: 2003 May 9
+    Author: Stefan Urbanek <urbanek@host.sk>
+ 
+    This file is part of the StepTalk project.
+ 
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+ 
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+ 
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ 
+ */
+
+#import <Foundation/NSString.h>
+
+@interface NSString (STSmalltalkAdditions)
+- (BOOL)containsString:(NSString *)aString;
+@end
diff --git a/Languages/Smalltalk/NSString+additions.m b/Languages/Smalltalk/NSString+additions.m
new file mode 100644
index 0000000..a7e01fa
--- /dev/null
+++ b/Languages/Smalltalk/NSString+additions.m
@@ -0,0 +1,39 @@
+/**
+    NSString-additions.h
+    Various methods for NSString
+ 
+    Copyright (c) 2002 Free Software Foundation
+ 
+    Date: 2003 May 9
+    Author: Stefan Urbanek <urbanek@host.sk>
+ 
+    This file is part of the StepTalk project.
+ 
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+ 
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+ 
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ 
+ */
+
+#import "NSString+additions.h"
+
+@implementation NSString (STSmalltalkAdditions)
+- (BOOL)containsString:(NSString *)aString
+{
+    NSRange range;
+    
+    range = [self rangeOfString:aString];
+    
+    return (range.location != NSNotFound);
+}
+@end