diff --git a/configure b/configure
index a7f2c3edd8..44a70cfa8c 100755
--- a/configure
+++ b/configure
@@ -3367,7 +3367,9 @@ if test "$vnc" = "yes" && test "$vnc_sasl" != "no" ; then
 int main(void) { sasl_server_init(NULL, "qemu"); return 0; }
 EOF
   # Assuming Cyrus-SASL installed in /usr prefix
-  vnc_sasl_cflags=""
+  # QEMU defines struct iovec in "qemu/osdep.h",
+  # we don't want libsasl to redefine it in <sasl/sasl.h>.
+  vnc_sasl_cflags="-DSTRUCT_IOVEC_DEFINED"
   vnc_sasl_libs="-lsasl2"
   if compile_prog "$vnc_sasl_cflags" "$vnc_sasl_libs" ; then
     vnc_sasl=yes