diff --git a/nyx/mmh3.c b/nyx/mmh3.c
index 89ab1096e9..65a46ff72b 100644
--- a/nyx/mmh3.c
+++ b/nyx/mmh3.c
@@ -48,7 +48,7 @@ FORCE_INLINE uint64_t fmix64(uint64_t k) {
     return k;
 }
 
-void mmh3_x86_32(const void *key, int len, uint32_t seed, void *out) {
+void mmh3_x86_32(const void *key, uint64_t len, uint32_t seed, void *out) {
     const uint8_t *data = (const uint8_t *) key;
     const int nblocks = len/4;
     uint32_t h1 = seed;
@@ -87,7 +87,7 @@ void mmh3_x86_32(const void *key, int len, uint32_t seed, void *out) {
     *(uint32_t *) out = h1;
 }
 
-void mmh3_x86_128(const void *key, const int len, uint32_t seed, void *out) {
+void mmh3_x86_128(const void *key, const uint64_t len, uint32_t seed, void *out) {
     const uint8_t *data = (const uint8_t *) key;
     const int nblocks = len/16;
 
@@ -219,7 +219,7 @@ void mmh3_x86_128(const void *key, const int len, uint32_t seed, void *out) {
     ((uint32_t *) out)[3] = h4;
 }
 
-void mmh3_x64_128(const void *key, const int len, const uint32_t seed, void *out) {
+void mmh3_x64_128(const void *key, const uint64_t len, const uint32_t seed, void *out) {
     const uint8_t *data = (const uint8_t *) key;
     const int nblocks = len/16;
     uint64_t h1 = seed;
diff --git a/nyx/mmh3.h b/nyx/mmh3.h
index a46a0bff1a..3bb2a2932d 100644
--- a/nyx/mmh3.h
+++ b/nyx/mmh3.h
@@ -5,8 +5,8 @@
 
 typedef unsigned __int128 uint128_t;
 
-void mmh3_x86_32(const void *key, int len, uint32_t seed, void *out);
-void mmh3_x86_128(const void *key, int len, uint32_t seed, void *out);
-void mmh3_x64_128(const void *key, int len, uint32_t seed, void *out);
+void mmh3_x86_32(const void *key, uint64_t len, uint32_t seed, void *out);
+void mmh3_x86_128(const void *key, uint64_t len, uint32_t seed, void *out);
+void mmh3_x64_128(const void *key, uint64_t len, uint32_t seed, void *out);
 
 #endif