diff --git a/packages/dts-generator/api-report/dts-generator.api.md b/packages/dts-generator/api-report/dts-generator.api.md
index 61ad88d..c149177 100644
--- a/packages/dts-generator/api-report/dts-generator.api.md
+++ b/packages/dts-generator/api-report/dts-generator.api.md
@@ -52,7 +52,9 @@ export interface Directives {
         [orgNamespace: string]: true | [true] | [true, "keep_original_ns"];
     };
     overlays: {
-        [libraryName: string]: ConcreteSymbol[];
+        [libraryName: string]: (ConcreteSymbol & {
+            esmOnly?: boolean;
+        })[];
     };
     typeTyposMap: {
         [orgType: string]: string;
diff --git a/packages/dts-generator/src/generate-from-objects.ts b/packages/dts-generator/src/generate-from-objects.ts
index f864ed4..4a16432 100644
--- a/packages/dts-generator/src/generate-from-objects.ts
+++ b/packages/dts-generator/src/generate-from-objects.ts
@@ -82,7 +82,7 @@ export interface Directives {
    * mapped to TypeScript and cannot be changed in a compatible way.
    */
   overlays: {
-    [libraryName: string]: ConcreteSymbol[];
+    [libraryName: string]: (ConcreteSymbol & { esmOnly?: boolean })[];
   };
 
   /**
@@ -160,6 +160,7 @@ export async function generateFromObjects(config: GenerateFromObjectsConfig) {
     apiObject,
     actualOptions.dependencyApiObjects,
     actualOptions.directives,
+    actualOptions.generateGlobals,
   );
 
   // Phase 2 - jsonToAst:
diff --git a/packages/dts-generator/src/phases/dts-code-gen.ts b/packages/dts-generator/src/phases/dts-code-gen.ts
index f69d680..8e22af2 100644
--- a/packages/dts-generator/src/phases/dts-code-gen.ts
+++ b/packages/dts-generator/src/phases/dts-code-gen.ts
@@ -630,6 +630,7 @@ function genField(ast: Variable) {
   text += JSDOC(ast) + NL;
   text += applyTsIgnore(ast);
   text += ast.static ? "static " : "";
+  text += ast.readonly ? "readonly " : "";
   text +=
     `${ast.name} : ${ast.type ? genType(ast.type, "property") : "any"}` + NL;
   return text;
diff --git a/packages/dts-generator/src/phases/json-fixer.ts b/packages/dts-generator/src/phases/json-fixer.ts
index 8b3c3ed..bef4853 100644
--- a/packages/dts-generator/src/phases/json-fixer.ts
+++ b/packages/dts-generator/src/phases/json-fixer.ts
@@ -31,7 +31,11 @@ const preparedCache = new Map();
  * @param apijson
  * @param directives
  */
-function mergeOverlays(apijson: ApiJSON, directives: Directives) {
+function mergeOverlays(
+  apijson: ApiJSON,
+  directives: Directives,
+  options = { generateGlobals: false },
+) {
   const overlays = directives.overlays && directives.overlays[apijson.library];
   if (overlays == null) {
     return; // no overlays defined
@@ -81,6 +85,10 @@ function mergeOverlays(apijson: ApiJSON, directives: Directives) {
   }
 
   overlays.forEach((overlay) => {
+    // do not generate esm-only symbols if generateGlobals is set
+    if (overlay.esmOnly && options.generateGlobals) {
+      return;
+    }
     log.verbose(`  ${overlay.name}`);
     const symbol = find(overlay.name);
     if (symbol == null) {
@@ -88,18 +96,25 @@ function mergeOverlays(apijson: ApiJSON, directives: Directives) {
       apijson.symbols.push(overlay);
       return;
     }
-    // overlay
+    // overlay needs to be merged into existing symbol
     Object.keys(overlay).forEach((prop) => {
       if (prop == "name") {
         return; // ignore name property, it's the 'primary key' and can't be changed
       }
       if (mapLikeProperties.has(prop)) {
-        if (!Array.isArray(symbol[prop])) {
-          symbol[prop] = overlay[prop];
+        // = methods, properties
+        if (!Array.isArray(symbol[prop]) && Array.isArray(overlay[prop])) {
+          symbol[prop] = overlay[prop].filter(
+            (item) => !options.generateGlobals || !item.esmOnly,
+          );
           return;
         }
         const symbolItems: ConcreteSymbol[] = symbol[prop];
         overlay[prop].forEach((overlayItem: ConcreteSymbol) => {
+          if (overlayItem.esmOnly && options.generateGlobals) {
+            // skip esm-only ones in globals mode
+            return;
+          }
           const item = symbolItems.find(
             (symbolItem) =>
               symbolItem.name === overlayItem.name &&
@@ -864,9 +879,9 @@ function markDeprecatedAliasesForEnums(
 function _prepareApiJson(
   json: ApiJSON,
   directives: Directives,
-  options = { mainLibrary: false },
+  options = { mainLibrary: false, generateGlobals: false },
 ) {
-  mergeOverlays(json, directives);
+  mergeOverlays(json, directives, { generateGlobals: options.generateGlobals });
   substituteSapClassInfoTypedef(json);
   convertCoreAndConfigurationIntoANamespace(json, directives);
   moveTypeParametersFromConstructorToClass(json);
@@ -904,17 +919,22 @@ export function fixApiJsons(
   targetLibJson: ApiJSON,
   dependencies: ApiJSON[],
   directives: Directives,
+  generateGlobals?: boolean,
 ) {
   // Part 1: "prepare JSON"
   let targetLibFixedJson = _prepareApiJson(targetLibJson, directives, {
     mainLibrary: true,
+    generateGlobals,
   });
 
   let depsFixedJsons: ApiJSON[] = dependencies.map((depjson) => {
     const key = `${depjson.library}-${depjson.version}`;
     let preparedjson = preparedCache.get(key);
     if (!preparedjson) {
-      preparedjson = _prepareApiJson(depjson, directives);
+      preparedjson = _prepareApiJson(depjson, directives, {
+        mainLibrary: false,
+        generateGlobals,
+      });
       preparedCache.set(key, preparedjson);
     }
     return JSON.parse(JSON.stringify(preparedjson)); // cloning needed to avoid multiple processing within the subsequent steps; // TODO: but this can likely be improved
diff --git a/packages/dts-generator/src/phases/json-to-ast.ts b/packages/dts-generator/src/phases/json-to-ast.ts
index d987e58..3cd7e7d 100644
--- a/packages/dts-generator/src/phases/json-to-ast.ts
+++ b/packages/dts-generator/src/phases/json-to-ast.ts
@@ -1197,7 +1197,10 @@ const buildNestedTypedefs = _.partialRight(
  * @returns
  */
 function buildVariable(property: ObjProperty): Variable {
-  assertKnownProps(["examples", "name", "type", "value", "optional"], property);
+  assertKnownProps(
+    ["examples", "name", "type", "value", "optional", "esmOnly", "readonly"],
+    property,
+  );
 
   const astNode: Variable = {
     kind: "Variable",
@@ -1205,6 +1208,7 @@ function buildVariable(property: ObjProperty): Variable {
     static: property.static === true,
     type: buildType(property.type),
     visibility: property.visibility,
+    readonly: property.readonly === true,
     optional: property.optional === true,
   };
 
diff --git a/packages/dts-generator/src/types/api-json.d.ts b/packages/dts-generator/src/types/api-json.d.ts
index f9603e5..b03bd24 100644
--- a/packages/dts-generator/src/types/api-json.d.ts
+++ b/packages/dts-generator/src/types/api-json.d.ts
@@ -257,6 +257,7 @@ export interface ObjProperty {
   export?: string;
   resource?: string;
   visibility?: "public" | "protected" | "private" | "restricted";
+  readonly?: boolean;
   static?: boolean;
   type: string;
   description?: string;
diff --git a/packages/dts-generator/src/types/ast.d.ts b/packages/dts-generator/src/types/ast.d.ts
index 02409e8..e1a8fe9 100644
--- a/packages/dts-generator/src/types/ast.d.ts
+++ b/packages/dts-generator/src/types/ast.d.ts
@@ -129,6 +129,7 @@ export interface Variable extends AstNode, UI5JSDocs {
   static?: boolean;
   type: Type;
   visibility: UI5Visibility;
+  readonly?: boolean;
   optional: boolean;
 }