diff --git a/Doxyfile b/Doxyfile
index 8f18c18..fc5cde9 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -44,7 +44,7 @@ PROJECT_NUMBER         =
 # for a project that appears at the top of each page and should give viewer a
 # quick idea about the purpose of the project. Keep the description short.
 
-PROJECT_BRIEF          = A An optimized prime number generator written in C.
+PROJECT_BRIEF          = "A An optimized prime number generator written in C."
 
 # With the PROJECT_LOGO tag one can specify a logo or an icon that is included
 # in the documentation. The maximum height of the logo should not exceed 55