diff --git a/Utilities/otbossim/src/ossim/CMakeLists.txt b/Utilities/otbossim/src/ossim/CMakeLists.txt
index 450a6235b2b7edb53ec73f6f57447becbd94ff02..88200916976641bb7759afdc8ce9afa46b930b6b 100644
--- a/Utilities/otbossim/src/ossim/CMakeLists.txt
+++ b/Utilities/otbossim/src/ossim/CMakeLists.txt
@@ -35,6 +35,8 @@ ENDIF(WIN32)
 
 INCLUDE_DIRECTORIES(${OTB_BINARY_DIR}/Utilities/otbgeotiff/)
 
+#Specify that we are making DLL here
+ADD_DEFINITION(-DOSSIMMAKINGDLL)
 
 # For alls platform (except MINGW):
 IF( NOT MINGW )