1 files changed, 1 insertions, 0 deletions
diff --git a/src/os.h b/src/os.h
index 554952df0..05dc70c9b 100644
--- a/src/os.h
+++ b/src/os.h
@@ -82,6 +82,7 @@
 # define INCL_DOSMISC
 # define INCL_DOSPROCESS
 # define INCL_DOSMODULEMGR
+# define INCL_DOSSEMAPHORES
 # include <os2.h>
 # define SQLITE_TEMPNAME_SIZE (CCHMAXPATHCOMP)
 #else