diff --git a/GNUmakefile b/GNUmakefile
index d56841b..ab47113 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -18,6 +18,7 @@ DBDS    += dbLoadTemplate.dbd
 
 SOURCES_T2 += strdup.c
 SOURCES_vxWorks   += asprintf.c
+SOURCES_WIN32 += asprintf.c
 HEADERS += strdup.h asprintf.h
 HEADERS += require.h