diff --git a/include/proto/sample.h b/include/proto/sample.h
index bcdd23baa..268e7a0d2 100644
--- a/include/proto/sample.h
+++ b/include/proto/sample.h
@@ -63,4 +63,15 @@ int sample_convert(struct sample *sample, int req_type)
 	return sample_casts[sample->data.type][req_type](sample);
 }
 
+static inline
+struct sample *smp_set_owner(struct sample *smp, struct proxy *px,
+                             struct session *sess, struct stream *strm, int opt)
+{
+	smp->px   = px;
+	smp->sess = sess;
+	smp->strm = strm;
+	smp->opt  = opt;
+	return smp;
+}
+
 #endif /* _PROTO_SAMPLE_H */
diff --git a/src/hlua.c b/src/hlua.c
index 9291517b1..2ed6f525d 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -3011,10 +3011,7 @@ __LJMP static int hlua_run_sample_fetch(lua_State *L)
 	memset(&smp, 0, sizeof(smp));
 
 	/* Run the sample fetch process. */
-	smp.px = hsmp->p;
-	smp.sess = hsmp->s->sess;
-	smp.strm = hsmp->s;
-	smp.opt = hsmp->dir & SMP_OPT_DIR;
+	smp_set_owner(&smp, hsmp->p, hsmp->s->sess, hsmp->s, hsmp->dir & SMP_OPT_DIR);
 	if (!f->process(args, &smp, f->kw, f->private)) {
 		if (hsmp->flags & HLUA_F_AS_STRING)
 			lua_pushstring(L, "");
@@ -3121,6 +3118,8 @@ __LJMP static int hlua_run_sample_conv(lua_State *L)
 		WILL_LJMP(lua_error(L));
 	}
 
+	smp_set_owner(&smp, hsmp->p, hsmp->s->sess, hsmp->s, hsmp->dir & SMP_OPT_DIR);
+
 	/* Apply expected cast. */
 	if (!sample_casts[smp.data.type][conv->in_type]) {
 		hlua_pusherror(L, "invalid input argument: cannot cast '%s' to '%s'",
@@ -3134,10 +3133,6 @@ __LJMP static int hlua_run_sample_conv(lua_State *L)
 	}
 
 	/* Run the sample conversion process. */
-	smp.px = hsmp->p;
-	smp.sess = hsmp->s->sess;
-	smp.strm = hsmp->s;
-	smp.opt = hsmp->dir & SMP_OPT_DIR;
 	if (!conv->process(args, &smp, conv->private)) {
 		if (hsmp->flags & HLUA_F_AS_STRING)
 			lua_pushstring(L, "");
diff --git a/src/sample.c b/src/sample.c
index 5a79955bc..7c2d9058f 100644
--- a/src/sample.c
+++ b/src/sample.c
@@ -1040,10 +1040,7 @@ struct sample *sample_process(struct proxy *px, struct session *sess,
 		memset(p, 0, sizeof(*p));
 	}
 
-	p->px   = px;
-	p->sess = sess;
-	p->strm = strm;
-	p->opt  = opt;
+	smp_set_owner(p, px, sess, strm, opt);
 	if (!expr->fetch->process(expr->arg_p, p, expr->fetch->kw, expr->fetch->private))
 		return NULL;