diff --git a/arkguard/src/configs/preset/es6_reserved_properties.json b/arkguard/src/configs/preset/es6_reserved_properties.json
index cf3d2dd8710b6ce79148d5b14e82fa66990dc34a..3dea97490ee3c4382839120a219f039eeabd031d 100644
--- a/arkguard/src/configs/preset/es6_reserved_properties.json
+++ b/arkguard/src/configs/preset/es6_reserved_properties.json
@@ -3403,6 +3403,7 @@
   "channelInterpretation",
   "char",
   "charAt",
+  "getCharByIndex",
   "charCode",
   "charCodeAt",
   "charIndex",
@@ -7881,4 +7882,4 @@
   "timeZone",
   "ResolvedDateTimeFormatOptions",
   "calendar"
-]
\ No newline at end of file
+]
diff --git a/ets2panda/compiler/scripts/signatures.yaml b/ets2panda/compiler/scripts/signatures.yaml
index 35f30fef05a85fdd091786419c521dc594dc8bde..bff22d355dd93cf474d78a861ac1b3e6790e7eee 100644
--- a/ets2panda/compiler/scripts/signatures.yaml
+++ b/ets2panda/compiler/scripts/signatures.yaml
@@ -320,7 +320,7 @@ signatures:
     ref: BUILTIN_STRING_LENGTH
 
   - callee: BUILTIN_STRING
-    method_name: charAt
+    method_name: getCharByIndex
     params: [PRIMITIVE_INT]
     return_type: PRIMITIVE_CHAR
     ref: BUILTIN_STRING_CHAR_AT
diff --git a/ets2panda/test/parser/ets/StringBase64.ets b/ets2panda/test/parser/ets/StringBase64.ets
index 2b3c6fddbec43ef1f16c285e24dfcc82c39cd366..13ddc755157f771285b896898763d705dddd2d22 100644
--- a/ets2panda/test/parser/ets/StringBase64.ets
+++ b/ets2panda/test/parser/ets/StringBase64.ets
@@ -22,21 +22,21 @@ export class StringBase64  {
         let length : int = data.length();
         let i : int ;
         for (i = 0; i < (length - 2); i += 3) {
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(data.charAt(i) >> 2));
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(((data.charAt(i) & 0x03) << 4) + (data.charAt(i + 1) >> 4)));
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(((data.charAt(i + 1) & 0x0f) << 2) + (data.charAt(i + 2) >> 6)));
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(data.charAt(i + 2) & 0x3f));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(data.getCharByIndex(i) >> 2));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(((data.getCharByIndex(i) & 0x03) << 4) + (data.getCharByIndex(i + 1) >> 4)));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(((data.getCharByIndex(i + 1) & 0x0f) << 2) + (data.getCharByIndex(i + 2) >> 6)));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(data.getCharByIndex(i + 2) & 0x3f));
         }
         if (length % 3 != 0) {
             i = length - (length % 3);
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(data.charAt(i) >> 2));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(data.getCharByIndex(i) >> 2));
             if ((length % 3) == 2) {
-                result.append(StringBase64.TO_BASE64_TABLE.charAt(((data.charAt(i) & 0x03) << 4) + (data.charAt(i + 1) >> 4)));
-                result.append(StringBase64.TO_BASE64_TABLE.charAt((data.charAt(i + 1) & 0x0f) << 2));
+                result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(((data.getCharByIndex(i) & 0x03) << 4) + (data.getCharByIndex(i + 1) >> 4)));
+                result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex((data.getCharByIndex(i + 1) & 0x0f) << 2));
                 result.append(StringBase64.BASE64PAD);
             }
             else {
-                result.append(StringBase64.TO_BASE64_TABLE.charAt((data.charAt(i) & 0x03) << 4));
+                result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex((data.getCharByIndex(i) & 0x03) << 4));
                 result.append(StringBase64.BASE64PAD);
                 result.append(StringBase64.BASE64PAD);
             }
@@ -48,8 +48,8 @@ export class StringBase64  {
         let leftbits : int = 0;
         let leftdata : int = 0;
         for (let i : int = 0; i < data.length(); i++) {
-            let c : int = StringBase64.TO_BINARY_TABLE[data.charAt(i) & 0x7f];
-            let padding : boolean = data.charAt(i) == StringBase64.BASE64PAD;
+            let c : int = StringBase64.TO_BINARY_TABLE[data.getCharByIndex(i) & 0x7f];
+            let padding : boolean = data.getCharByIndex(i) == StringBase64.BASE64PAD;
             if (c == -1) {
                 continue;
             }
diff --git a/ets2panda/test/runtime/ets/RegisterSpiller.ets b/ets2panda/test/runtime/ets/RegisterSpiller.ets
index e994742a8090c56b589c5f328021f69316278432..a0afe3a7af4ef7321b017283b5ae4da6b786d197 100644
--- a/ets2panda/test/runtime/ets/RegisterSpiller.ets
+++ b/ets2panda/test/runtime/ets/RegisterSpiller.ets
@@ -15,9 +15,9 @@
 
 function main(): void {
     let str: String = "hello\nworld\n";
-    assert str.charAt(2) == c'l';
+    assert str.getCharByIndex(2) == c'l';
     assert str.length() == 12;
-    assert str.charAt(str.length() - 1) == c'\n';
+    assert str.getCharByIndex(str.length() - 1) == c'\n';
 
     let a: String = "abc";
     let b: String = "ace";
diff --git a/ets2panda/test/runtime/ets/StringBase64.ets b/ets2panda/test/runtime/ets/StringBase64.ets
index 17e894db3d19df9f7cf25ab5aa797c8f813d13d0..87c5dcb8e676af4ba5f83bcb16d74b1e26489779 100644
--- a/ets2panda/test/runtime/ets/StringBase64.ets
+++ b/ets2panda/test/runtime/ets/StringBase64.ets
@@ -22,21 +22,21 @@ export class StringBase64  {
         let length : int = data.length();
         let i : int ;
         for (i = 0; i < (length - 2); i += 3) {
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(data.charAt(i) >> 2));
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(((data.charAt(i) & 0x03) << 4) + (data.charAt(i + 1) >> 4)));
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(((data.charAt(i + 1) & 0x0f) << 2) + (data.charAt(i + 2) >> 6)));
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(data.charAt(i + 2) & 0x3f));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(data.getCharByIndex(i) >> 2));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(((data.getCharByIndex(i) & 0x03) << 4) + (data.getCharByIndex(i + 1) >> 4)));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(((data.getCharByIndex(i + 1) & 0x0f) << 2) + (data.getCharByIndex(i + 2) >> 6)));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(data.getCharByIndex(i + 2) & 0x3f));
         }
         if (length % 3 != 0) {
             i = length - (length % 3);
-            result.append(StringBase64.TO_BASE64_TABLE.charAt(data.charAt(i) >> 2));
+            result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(data.getCharByIndex(i) >> 2));
             if ((length % 3) == 2) {
-                result.append(StringBase64.TO_BASE64_TABLE.charAt(((data.charAt(i) & 0x03) << 4) + (data.charAt(i + 1) >> 4)));
-                result.append(StringBase64.TO_BASE64_TABLE.charAt((data.charAt(i + 1) & 0x0f) << 2));
+                result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex(((data.getCharByIndex(i) & 0x03) << 4) + (data.getCharByIndex(i + 1) >> 4)));
+                result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex((data.getCharByIndex(i + 1) & 0x0f) << 2));
                 result.append(StringBase64.BASE64PAD);
             }
             else {
-                result.append(StringBase64.TO_BASE64_TABLE.charAt((data.charAt(i) & 0x03) << 4));
+                result.append(StringBase64.TO_BASE64_TABLE.getCharByIndex((data.getCharByIndex(i) & 0x03) << 4));
                 result.append(StringBase64.BASE64PAD);
                 result.append(StringBase64.BASE64PAD);
             }
@@ -48,8 +48,8 @@ export class StringBase64  {
         let leftbits : int = 0;
         let leftdata : int = 0;
         for (let i : int = 0; i < data.length(); i++) {
-            let c : int = StringBase64.TO_BINARY_TABLE[data.charAt(i) & 0x7f];
-            let padding : boolean = data.charAt(i) == StringBase64.BASE64PAD;
+            let c : int = StringBase64.TO_BINARY_TABLE[data.getCharByIndex(i) & 0x7f];
+            let padding : boolean = data.getCharByIndex(i) == StringBase64.BASE64PAD;
             if (c == -1) {
                 continue;
             }
diff --git a/ets2panda/test/runtime/ets/skippedTest.ets b/ets2panda/test/runtime/ets/skippedTest.ets
index f40252c2b43905e0402378b8090685f8a00f8795..07456579f61f99371b99a3f2061dd2b8667f8d03 100644
--- a/ets2panda/test/runtime/ets/skippedTest.ets
+++ b/ets2panda/test/runtime/ets/skippedTest.ets
@@ -24,7 +24,7 @@ function main(): void {
     let n5: double = 44.44;
     console.print(str);
     console.println();
-    console.print(str.charAt(2));
+    console.print(str.getCharByIndex(2));
     console.println();
     console.print(str.length());
     console.println();