--- src/libepub/epub_shared.h.orig
+++ src/libepub/epub_shared.h
@@ -8,7 +8,7 @@
 #  define EPUB_EXPORT __declspec(dllimport)
 # endif
 #else
-# define EPUB_EXPORT
+# define EPUB_EXPORT __attribute__ ((visibility ("default")))
 #endif
 
 /**
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -15,7 +15,7 @@ find_package(LibXml2 REQUIRED)
 find_package(LibZip REQUIRED)
 
 if(CMAKE_C_COMPILER_ID MATCHES GNU)
-  set(CMAKE_C_FLAGS "-Wall -W -Wno-long-long -Wundef -Wcast-align -Werror-implicit-function-declaration -Wchar-subscripts -Wpointer-arith -Wwrite-strings -Wformat-security -Wmissing-format-attribute -Wshadow -fno-common ${CMAKE_C_FLAGS}")
+  set(CMAKE_C_FLAGS "-Wall -W -Wno-long-long -Wundef -Wcast-align -Werror-implicit-function-declaration -Wchar-subscripts -Wpointer-arith -Wwrite-strings -Wformat-security -Wmissing-format-attribute -Wshadow -fno-common -fvisibility=hidden ${CMAKE_C_FLAGS}")
 endif(CMAKE_C_COMPILER_ID MATCHES GNU)
 if(MSVC)
   add_definitions(-D_CRT_SECURE_NO_WARNINGS)