jruby
diff --git a/‎core/src/main/java/org/jruby/truffle/runtime/core/RubyString.java
+2-1 b/‎core/src/main/java/org/jruby/truffle/runtime/core/RubyString.java
+2-1
diff --git a/‎spec/truffle/tags/core/fixnum/to_s_tags.txt
-2 b/‎spec/truffle/tags/core/fixnum/to_s_tags.txt
-2
@@ -12,6 +12,7 @@
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import org.jcodings.Encoding;
 import org.jcodings.specific.ASCIIEncoding;
+import org.jcodings.specific.USASCIIEncoding;
 import org.jcodings.specific.UTF8Encoding;
 import org.jruby.runtime.Helpers;
 import org.jruby.truffle.nodes.RubyNode;
@@ -34,7 +35,7 @@ public RubyString(RubyClass stringClass, ByteList bytes) {
     }
 
     public static RubyString fromJavaString(RubyClass stringClass, String string) {
-        return new RubyString(stringClass, new ByteList(org.jruby.RubyEncoding.encodeUTF8(string), ASCIIEncoding.INSTANCE, false));
+        return new RubyString(stringClass, new ByteList(org.jruby.RubyEncoding.encodeUTF8(string), USASCIIEncoding.INSTANCE, false));
     }
 
     public static RubyString fromByteList(RubyClass stringClass, ByteList bytes) {
Original file line number	Diff line number	Diff line change
`@@ -12,6 +12,7 @@`
`12`	`12`	`import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;`
`13`	`13`	`import org.jcodings.Encoding;`
`14`	`14`	`import org.jcodings.specific.ASCIIEncoding;`
	`15`	`+import org.jcodings.specific.USASCIIEncoding;`
`15`	`16`	`import org.jcodings.specific.UTF8Encoding;`
`16`	`17`	`import org.jruby.runtime.Helpers;`
`17`	`18`	`import org.jruby.truffle.nodes.RubyNode;`
`@@ -34,7 +35,7 @@ public RubyString(RubyClass stringClass, ByteList bytes) {`
`34`	`35`	`}`
`35`	`36`
`36`	`37`	`public static RubyString fromJavaString(RubyClass stringClass, String string) {`
`37`		`- return new RubyString(stringClass, new ByteList(org.jruby.RubyEncoding.encodeUTF8(string), ASCIIEncoding.INSTANCE, false));`
	`38`	`+ return new RubyString(stringClass, new ByteList(org.jruby.RubyEncoding.encodeUTF8(string), USASCIIEncoding.INSTANCE, false));`
`38`	`39`	`}`
`39`	`40`
`40`	`41`	`public static RubyString fromByteList(RubyClass stringClass, ByteList bytes) {`