diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 52c38fd33..09d427a49 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -1660,7 +1660,8 @@ static bool prepend_lxc_header(char *path, const char *t, char *const argv[])
 	FILE *f;
 	int ret = -1;
 #if HAVE_OPENSSL
-	int i, md_len = 0;
+	int i;
+	unsigned int md_len = 0;
 	unsigned char md_value[EVP_MAX_MD_SIZE];
 	char *tpath;
 #endif
diff --git a/src/lxc/utils.c b/src/lxc/utils.c
index bf4a9c2cb..9ddbabfc8 100644
--- a/src/lxc/utils.c
+++ b/src/lxc/utils.c
@@ -333,7 +333,7 @@ again:
 #ifdef HAVE_OPENSSL
 #include <openssl/evp.h>
 
-static int do_sha1_hash(const char *buf, int buflen, unsigned char *md_value, int *md_len)
+static int do_sha1_hash(const char *buf, int buflen, unsigned char *md_value, unsigned int *md_len)
 {
 	EVP_MD_CTX *mdctx;
 	const EVP_MD *md;
@@ -353,7 +353,7 @@ static int do_sha1_hash(const char *buf, int buflen, unsigned char *md_value, in
 	return 0;
 }
 
-int sha1sum_file(char *fnam, unsigned char *digest, int *md_len)
+int sha1sum_file(char *fnam, unsigned char *digest, unsigned int *md_len)
 {
 	char *buf;
 	int ret;
diff --git a/src/lxc/utils.h b/src/lxc/utils.h
index dd6404f0b..c1667e8c4 100644
--- a/src/lxc/utils.h
+++ b/src/lxc/utils.h
@@ -99,7 +99,7 @@ extern int wait_for_pid(pid_t pid);
 extern int lxc_wait_for_pid_status(pid_t pid);
 
 #if HAVE_OPENSSL
-extern int sha1sum_file(char *fnam, unsigned char *md_value, int *md_len);
+extern int sha1sum_file(char *fnam, unsigned char *md_value, unsigned int *md_len);
 #endif
 
 /* initialize rand with urandom */