diff --git a/doc/jsweet-language-specifications.tex b/doc/jsweet-language-specifications.tex
index 6635f3a5..ad92f075 100644
--- a/doc/jsweet-language-specifications.tex
+++ b/doc/jsweet-language-specifications.tex
@@ -126,6 +126,7 @@ Here follows the list of allowed Java classes in JSweet:
 				\item \texttt{indexOf(java.lang.String)}
 				\item \texttt{lastIndexOf(java.lang.String)}
 				\item \texttt{lastIndexOf(java.lang.String,int)}
+				\item \texttt{length()} (transpiles to \texttt{length})
 				\item \texttt{substring(int)}
 				\item \texttt{substring(int,int)} (with the JavaScript behavior)
 				\item \texttt{replace(java.lang.String,java.lang.String)}
diff --git a/src/main/java/org/jsweet/transpiler/TypeChecker.java b/src/main/java/org/jsweet/transpiler/TypeChecker.java
index 445b8e69..2213a51c 100644
--- a/src/main/java/org/jsweet/transpiler/TypeChecker.java
+++ b/src/main/java/org/jsweet/transpiler/TypeChecker.java
@@ -109,6 +109,7 @@ public class TypeChecker {
 		AUTHORIZED_STRING_METHODS.add("trim()");
 		AUTHORIZED_STRING_METHODS.add("toLowerCase()");
 		AUTHORIZED_STRING_METHODS.add("toUpperCase()");
+		AUTHORIZED_STRING_METHODS.add("length()");
 
 		FORBIDDEN_JDK_FUNCTIONAL_METHODS.add("and");
 		FORBIDDEN_JDK_FUNCTIONAL_METHODS.add("negate");
diff --git a/src/main/java/org/jsweet/transpiler/typescript/Java2TypeScriptAdapter.java b/src/main/java/org/jsweet/transpiler/typescript/Java2TypeScriptAdapter.java
index 60d401bc..276cbe98 100644
--- a/src/main/java/org/jsweet/transpiler/typescript/Java2TypeScriptAdapter.java
+++ b/src/main/java/org/jsweet/transpiler/typescript/Java2TypeScriptAdapter.java
@@ -282,7 +282,12 @@ public class Java2TypeScriptAdapter extends AbstractPrinterAdapter {
 			getPrinter().print(")");
 			return true;
 		}
+		if (matchesMethod(targetClassName, targetMethodName, String.class.getName(), "length")) {
+			getPrinter().print(invocation.meth);
+			return true;
+		}
 
+		
 		if (matchesMethod(targetClassName, targetMethodName, null, INDEXED_GET_FUCTION_NAME)) {
 			if (isWithinGlobals(targetClassName)) {
 				report(invocation, JSweetProblem.GLOBAL_INDEXER_GET);
diff --git a/src/test/java/org/jsweet/test/transpiler/ApiTests.java b/src/test/java/org/jsweet/test/transpiler/ApiTests.java
index 738c5010..c3862786 100644
--- a/src/test/java/org/jsweet/test/transpiler/ApiTests.java
+++ b/src/test/java/org/jsweet/test/transpiler/ApiTests.java
@@ -55,6 +55,7 @@ public class ApiTests extends AbstractTest {
 			assertEquals("testc", result.<String> get("s4"));
 			assertEquals(2, result.<Number> get("i1").intValue());
 			assertEquals(-1, result.<Number> get("i2").intValue());
+			assertEquals(4, result.<Number> get("l").intValue());
 		}, getSourceFile(JdkInvocations.class));
 	}
 
diff --git a/src/test/java/source/api/JdkInvocations.java b/src/test/java/source/api/JdkInvocations.java
index 6e8ae4a5..efd56101 100644
--- a/src/test/java/source/api/JdkInvocations.java
+++ b/src/test/java/source/api/JdkInvocations.java
@@ -36,6 +36,7 @@ public class JdkInvocations {
 		$export("s4", s.concat("c"));
 		$export("i1", s.indexOf("s"));
 		$export("i2", s.lastIndexOf("gg"));
+		$export("l", s.length());
 		s.lastIndexOf("", 10);
 		Other4 o2 = new Other4();
 		o2.toString();