diff --git a/lib/Epub/Epub/parsers/ContentOpfParser.cpp b/lib/Epub/Epub/parsers/ContentOpfParser.cpp
index a88c2938..fd0708fd 100644
--- a/lib/Epub/Epub/parsers/ContentOpfParser.cpp
+++ b/lib/Epub/Epub/parsers/ContentOpfParser.cpp
@@ -327,6 +327,9 @@ void XMLCALL ContentOpfParser::characterData(void* userData, const XML_Char* s,
   }
 
   if (self->state == IN_BOOK_AUTHOR) {
+    if (!self->author.empty()) {
+      self->author.append(", ");  // Add separator for multiple authors
+    }
     self->author.append(s, len);
     return;
   }