diff --git a/creole.c b/creole.c
index 9df59bd..d5f6648 100644
--- a/creole.c
+++ b/creole.c
@@ -559,7 +559,7 @@ load_into_array(const struct creole_reader *start, creole_word *buf, size_t bufl
 {
 	size_t i = 0;
 	struct creole_word w;
-	struct creole_reader r = start;
+	struct creole_reader r = *start;
 
 	while (creole_decode(&r, &w) && i < buflen) {
 		buf[i++] = w.word;
@@ -573,7 +573,7 @@ upsilon_load_waveform(struct creole_env *env, creole_word slot,
                       creole_word db)
 {
 	creole_word buf[MAX_WL_SIZE];
-	size_t len = load_into_array(env->dats[db], buf, ARRAY_SIZE(buf));
+	size_t len = load_into_array(env->dats + db, buf, ARRAY_SIZE(buf));
 	if (len < MAX_WL_SIZE)
 		return 0;
 	return waveform_load(buf, slot, K_FOREVER);
@@ -591,12 +591,13 @@ upsilon_sendval(struct creole_env *env, creole_word num)
 static creole_word
 upsilon_senddat(struct creole_env *env, creole_word db)
 {
-	char buf[128];
+#define SENDDAT_BUFLEN 128
+	char buf[SENDDAT_BUFLEN];
 	struct bufptr bp = {buf, 0};
 	struct creole_word w;
-	struct creole_reader r = start;
+	struct creole_reader r = env->dats[db];
 
-	while (creole_decode(&r, &w) && bp.left < buflen) {
+	while (creole_decode(&r, &w) && bp.left < SENDDAT_BUFLEN) {
 		if (w.word > 0xFF)
 			return -EINVAL;
 		buf[bp.left++] = w.word;
@@ -641,8 +642,8 @@ enum creole_run_ret creole_step(struct creole_env *env, creole_word *sc)
 
 	switch (ins.opcode) {
 	case CREOLE_DB:
-		env->dats[ins->w[0]].p = ins->datapt;
-		env->dats[ins->w[0]].left = ins->dataptlen;
+		env->dats[ins.w[0]].p = ins.datapt;
+		env->dats[ins.w[0]].left = ins.dataptlen;
 		break;
 
 	case CREOLE_PUSH:
@@ -753,7 +754,7 @@ enum creole_run_ret creole_step(struct creole_env *env, creole_word *sc)
 		check(read_val(env, &ins, 0, &a1));
 		check(read_val(env, &ins, 0, &a2));
 
-		if (valid_reglen(env, a1) && valid_reglen(env, a2)) {
+		if (valid_register(env, a1) && valid_register(env, a2)) {
 			a0 = cloop_read(a0, env->reg + a1, env->reg + a2, K_FOREVER);
 			check(creole_push(env, a0));
 		} else {
@@ -792,7 +793,7 @@ enum creole_run_ret creole_step(struct creole_env *env, creole_word *sc)
 
 	case CREOLE_SENDVAL:
 		check(read_val(env, &ins, 0, &a0));
-		check(creole_push(env, upsilon_sendval(a0)));
+		check(creole_push(env, upsilon_sendval(env, a0)));
 		break;
 
 	case CREOLE_SENDDAT: