diff --git a/teavm-classlib/src/main/java/org/teavm/classlib/java/lang/TString.java b/teavm-classlib/src/main/java/org/teavm/classlib/java/lang/TString.java
index e8dcf653f..b636dac46 100644
--- a/teavm-classlib/src/main/java/org/teavm/classlib/java/lang/TString.java
+++ b/teavm-classlib/src/main/java/org/teavm/classlib/java/lang/TString.java
@@ -22,6 +22,7 @@ import org.teavm.classlib.java.util.TArrays;
 import org.teavm.classlib.java.util.TComparator;
 import org.teavm.classlib.java.util.THashMap;
 import org.teavm.classlib.java.util.TMap;
+import org.teavm.classlib.java.util.regex.TPattern;
 import org.teavm.dependency.PluggableDependency;
 import org.teavm.javascript.ni.InjectedBy;
 import org.teavm.javascript.ni.Rename;
@@ -613,4 +614,16 @@ public class TString extends TObject implements TSerializable, TComparable<TStri
         }
         return interned;
     }
+
+    public boolean matches(String regex) {
+        return TPattern.matches(regex, this.toString());
+    }
+
+    public String[] split(String regex) {
+        return TPattern.compile(regex).split(this.toString());
+    }
+
+    public String[] split(String regex, int limit) {
+        return TPattern.compile(regex).split(this.toString(), limit);
+    }
 }
diff --git a/teavm-classlib/src/main/java/org/teavm/classlib/java/util/regex/TMatcher.java b/teavm-classlib/src/main/java/org/teavm/classlib/java/util/regex/TMatcher.java
index ed68b6f8f..2a945a351 100644
--- a/teavm-classlib/src/main/java/org/teavm/classlib/java/util/regex/TMatcher.java
+++ b/teavm-classlib/src/main/java/org/teavm/classlib/java/util/regex/TMatcher.java
@@ -316,6 +316,10 @@ public final class TMatcher implements TMatchResult {
      */
     @Override
     public String group(int group) {
+        if (group < 0 || group > matchResult.groupCount()) {
+            throw new IndexOutOfBoundsException("Index " + group + " if out of range [0; " +
+                    matchResult.groupCount() + ")");
+        }
         return matchResult.group(group);
     }