OK, I've changed my line to LDFLAGS = -L$(INCLUDE_SEAL_LIB) -lseal -lpthread In my Makefile this command is written like this (line numbers are just for orientation) 1: seal_diff_cpp.so: seal_diff_cpp.o 2: $(CXX) -Wl,--no-undefined -shared -o seal_diff_cpp.so seal_diff_cpp.o $(LDFLAGS) 3: Or do you mean that it suppose to be like that? 1: seal_diff_cpp.so: seal_diff_cpp.o $(CXX) -Wl,--no-undefined -shared -o seal_diff_cpp.so seal_diff_cpp.o $(LDFLAGS) -- Sent from: http://www.postgresql-archive.org/PostgreSQL-general-f1843780.html