diff --git a/src/modules/pagebreak/PageBreakModule.ts b/src/modules/pagebreak/PageBreakModule.ts
index bca6ad25..6913b5bd 100644
--- a/src/modules/pagebreak/PageBreakModule.ts
+++ b/src/modules/pagebreak/PageBreakModule.ts
@@ -171,6 +171,9 @@ export class PageBreakModule implements ReaderModule {
     setTimeout(() => {
       const body = this.delegate.iframes[0].contentDocument?.body;
       let pageBreaks = body?.querySelectorAll('[*|type="pagebreak"]');
+      if (pageBreaks?.length === 0) {
+        pageBreaks = body?.querySelectorAll("[epub\\:type='pagebreak']");
+      }
       let self = this;
 
       function getCssSelector(element: Element): string {
diff --git a/src/navigator/IFrameNavigator.ts b/src/navigator/IFrameNavigator.ts
index 57ad4e65..10a5dd22 100644
--- a/src/navigator/IFrameNavigator.ts
+++ b/src/navigator/IFrameNavigator.ts
@@ -1527,10 +1527,13 @@ export class IFrameNavigator extends EventEmitter implements Navigator {
     for (const iframe of this.iframes) {
       const head = iframe.contentDocument?.head;
       if (head) {
-        head.insertBefore(
-          IFrameNavigator.createBase(this.currentChapterLink.href),
-          head.firstChild
-        );
+        const bases = iframe.contentDocument.getElementsByTagName("base");
+        if (bases.length === 0) {
+          head.insertBefore(
+            IFrameNavigator.createBase(this.currentChapterLink.href),
+            head.firstChild
+          );
+        }
 
         this.injectables?.forEach((injectable) => {
           if (injectable.type === "style") {
@@ -1622,10 +1625,13 @@ export class IFrameNavigator extends EventEmitter implements Navigator {
       const parser = new DOMParser();
       const doc = parser.parseFromString(content, "application/xhtml+xml");
       if (doc.head) {
-        doc.head.insertBefore(
-          IFrameNavigator.createBase(href),
-          doc.head.firstChild
-        );
+        const bases = doc.getElementsByTagName("base");
+        if (bases.length === 0) {
+          doc.head.insertBefore(
+            IFrameNavigator.createBase(href),
+            doc.head.firstChild
+          );
+        }
       }
       const newHTML = doc.documentElement.outerHTML;
       const iframeDoc = self.iframes[0].contentDocument;
@@ -1640,10 +1646,13 @@ export class IFrameNavigator extends EventEmitter implements Navigator {
       const parser = new DOMParser();
       const doc = parser.parseFromString(content, "application/xhtml+xml");
       if (doc.head) {
-        doc.head.insertBefore(
-          IFrameNavigator.createBase(href),
-          doc.head.firstChild
-        );
+        const bases = doc.getElementsByTagName("base");
+        if (bases.length === 0) {
+          doc.head.insertBefore(
+            IFrameNavigator.createBase(href),
+            doc.head.firstChild
+          );
+        }
       }
       const newHTML = doc.documentElement.outerHTML;
       const iframeDoc = self.iframes[1].contentDocument;