diff --git a/src/include/janet.h b/src/include/janet.h
index b07197d6..e0c2f392 100644
--- a/src/include/janet.h
+++ b/src/include/janet.h
@@ -1539,6 +1539,7 @@ JANET_API JanetRNG *janet_default_rng(void);
 JANET_API void janet_rng_seed(JanetRNG *rng, uint32_t seed);
 JANET_API void janet_rng_longseed(JanetRNG *rng, const uint8_t *bytes, int32_t len);
 JANET_API uint32_t janet_rng_u32(JanetRNG *rng);
+JANET_API double janet_rng_double(JanetRNG *rng);
 
 /* Array functions */
 JANET_API JanetArray *janet_array(int32_t capacity);