compile error with 0.3.4

I am compiling v0.3.4 (4247a7b24dcced236bc424ff723e06067a723acc) from within a debian stretch based Linux container. here is the trimmed output where the errors occur:

$ cmake -G Ninja -DCMAKE_BUILD_TYPE=Release -DCEF_ROOT=/wrk/cef-pdf/cef/cef_binary_3.3359.1774.gd49d25f_linux64_minimal
[166/180] Linking CXX static library libcef_dll_wrapper/libcef_dll_wrapper.a
[167/180] Building CXX object src/CMakeFiles/cef-pdf.dir/Job/Job.cpp.o
[168/180] Building CXX object src/CMakeFiles/cef-pdf.dir/SchemeHandlerFactory.cpp.o
[169/180] Building CXX object src/CMakeFiles/cef-pdf.dir/Server/SessionManager.cpp.o
FAILED: src/CMakeFiles/cef-pdf.dir/Server/SessionManager.cpp.o
/usr/bin/c++   -DASIO_NO_TYPEID -DASIO_STANDALONE -DNDEBUG -D_FILE_OFFSET_BITS=64 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -Iasio -Icef/cef_binary_3.3359.1774.gd49d25f_linux64_minimal -O3 -DNDEBUG   -fno-strict-aliasing -fPIC -fstack-protector -funwind-tables -fvisibility=hidden --param=ssp-buffer-size=4 -pipe -pthread -Wall -Werror -Wno-missing-field-initializers -Wno-unused-parameter -Wno-error=comment -m64 -march=x86-64 -fno-exceptions -fno-rtti -fno-threadsafe-statics -fvisibility-inlines-hidden -std=gnu++11 -Wsign-compare -Wno-literal-suffix -Wno-narrowing -O2 -fdata-sections -ffunction-sections -fno-ident -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fexceptions -MD -MT src/CMakeFiles/cef-pdf.dir/Server/SessionManager.cpp.o -MF src/CMakeFiles/cef-pdf.dir/Server/SessionManager.cpp.o.d -o src/CMakeFiles/cef-pdf.dir/Server/SessionManager.cpp.o -c /wrk/cef-pdf/src/Server/SessionManager.cpp
In file included from /wrk/cef-pdf/src/Server/Session.h:4:0,
                 from /wrk/cef-pdf/src/Server/SessionManager.h:4,
                 from /wrk/cef-pdf/src/Server/SessionManager.cpp:1:
/wrk/cef-pdf/src/Server/../Client.h:128:18: error: 'virtual bool cefpdf::Client::OnBeforeBrowse(CefRefPtr<CefBrowser>, CefRefPtr<CefFrame>, CefRefPtr<CefRequest>, bool)' marked 'override', but does not override
     virtual bool OnBeforeBrowse(
                  ^~~~~~~~~~~~~~
[170/180] Building CXX object src/CMakeFiles/cef-pdf.dir/Job/Manager.cpp.o
[171/180] Building CXX object src/CMakeFiles/cef-pdf.dir/main.cpp.o
FAILED: src/CMakeFiles/cef-pdf.dir/main.cpp.o

any ideas?

spajak / cef-pdf

compile error with 0.3.4 #28