diff --git a/include/osdp_export.h b/include/osdp_export.h
index 9f50e8d..a9267d9 100644
--- a/include/osdp_export.h
+++ b/include/osdp_export.h
@@ -22,7 +22,9 @@
 
 /* ---------- Export / Import / Visibility ---------- */
 #if defined(_WIN32) || defined(__CYGWIN__)
-  #if defined(BUILDING_API)
+  #if defined(OSDP_STATIC_DEFINE)
+    #define API_EXPORT
+  #elif defined(BUILDING_API)
     #if defined(__GNUC__)
       #define API_EXPORT __attribute__ ((dllexport))
     #else
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index da73539..1112a0a 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -205,6 +205,7 @@ endif()
 set(LIB_OSDP_UTILS_SRC ${LIB_OSDP_UTILS_SRC} PARENT_SCOPE)
 
 add_library(${LIB_OSDP_SHARED} SHARED ${LIB_OSDP_SOURCES} ${LIB_OSDP_UTILS_SRC})
+target_compile_definitions(${LIB_OSDP_SHARED} PRIVATE BUILDING_API)
 if (OpenSSL_FOUND)
 	target_link_libraries(${LIB_OSDP_SHARED} PUBLIC OpenSSL::Crypto)
 elseif (MbedTLS_FOUND)