diff --git a/Installation/install_cgal b/Installation/install_cgal
index f4dfb3073c0..0df7c189b40 100755
--- a/Installation/install_cgal
+++ b/Installation/install_cgal
@@ -916,7 +916,7 @@ set_compiler_flags()
 	    ;;
 	*SunOS*5.*CC*)
 	    #### settings for sunpro compiler on solaris
-	    ADDITIONAL_CXXFLAGS="-pto -D_RWSTD_ALLOCATOR"
+	    ADDITIONAL_CXXFLAGS="-D_RWSTD_ALLOCATOR"
 	    CGAL_LIB_CREATE="\$(CGAL_CXX) -xar -o ''"
 	    CGAL_SHARED_LIB_CXXFLAGS="-pic"
 	    CGAL_SHARED_LIB_CREATE="\$(CGAL_CXX) -G"