changed : dll : only approved ZSTD symbols are now exposed. All other symbols remain internal.
diff --git a/lib/Makefile b/lib/Makefile
index bf1088d..44c64b8 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -70,7 +70,7 @@
 	@$(CC) $(FLAGS) -c $^
 	@$(AR) $(ARFLAGS) $@ *.o
 
-$(LIBZSTD): LDFLAGS += -shared -fPIC
+$(LIBZSTD): LDFLAGS += -shared -fPIC -fvisibility=hidden
 $(LIBZSTD): $(ZSTD_FILES)
 	@echo compiling dynamic library $(LIBVER)
 ifneq (,$(filter Windows%,$(OS)))