diff --git a/c++/src/cpp_doc_config b/c++/src/cpp_doc_config
index 13be1308bc..53d9a7dbbc 100644
--- a/c++/src/cpp_doc_config
+++ b/c++/src/cpp_doc_config
@@ -38,7 +38,7 @@ PROJECT_NAME           = "HDF5 C++ API"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = "HDF5 version 1.9.227 currently under development"
+PROJECT_NUMBER         = HDF5 version 1.9.227 currently under development
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a