diff --git a/src/util/srp.cpp b/src/util/srp.cpp
index 4c1a772e..9aed9eb0 100644
--- a/src/util/srp.cpp
+++ b/src/util/srp.cpp
@@ -39,6 +39,7 @@
 #include <cstdlib>
 #include <cstring>
 #include <cstdio>
+#include <cstdint>
 
 #include <config.h>
 
@@ -418,7 +419,7 @@ static SRP_Result H_nn(
 }
 
 static SRP_Result H_ns(mpz_t result, SRP_HashAlgorithm alg, const unsigned char *n,
-	size_t len_n, const unsigned char *bytes, size_t len_bytes)
+	size_t len_n, const unsigned char *bytes, uint32_t len_bytes)
 {
 	unsigned char buff[SHA512_DIGEST_LENGTH];
 	size_t nbytes = len_n + len_bytes;