diff --git a/fastrand.h b/fastrand.h
index c5b18b9..e1d5c9d 100644
--- a/fastrand.h
+++ b/fastrand.h
@@ -24,13 +24,13 @@ static inline rand_state init_rand() {
 #endif /* NO_CSTDLIB */
 
 // 32-bit LCG
-static inline uint32_t lcg(uint32_t *state) {
+static inline uint32_t lcg(rand_state *state) {
 	*state = *state * 1664525u + 1013904223u;
 	return *state;
 }
 
 /** Pick a "reasonably random" number in [0, until-1] without modulus */
-static inline uint32_t rand_until(uint32_t *state, uint32_t until) {
+static inline uint32_t rand_until(rand_state *state, uint32_t until) {
 	uint32_t rand = lcg(state);
 	// Multiply by "until", take the upper 32 bits of the 64-bit result
 	return (uint32_t)(((uint64_t)rand * until) >> 32);
@@ -44,7 +44,7 @@ static inline uint32_t rand_until(uint32_t *state, uint32_t until) {
  * @param to The biggest possible value + 1
  * @returns A value in [from, to) interval
  */
-static inline uint32_t rand_between(uint32_t *state, uint32_t from, uint32_t to) {
+static inline uint32_t rand_between(rand_state *state, uint32_t from, uint32_t to) {
 	return from + rand_until(state, to - from);
 }