diff --git a/src/shamir.c b/src/shamir.c
index 890f4c4..1e4b716 100644
--- a/src/shamir.c
+++ b/src/shamir.c
@@ -76,7 +76,7 @@ int32_t split_secret(
         // just return share_count copies of the secret
         uint8_t *share = result;
         for(uint8_t i=0; i< share_count; ++i, share += secret_length) {
-            for(uint8_t j=0; j<secret_length; ++j) {
+            for (uint8_t j = 0; j < (uint8_t) secret_length; ++j) {
                 share[j] = secret[j];
             }
         }
@@ -139,7 +139,7 @@ int32_t recover_secret(
     uint8_t valid = 1;
 
     if(threshold == 1) {
-        for(uint8_t j=0; j<share_length; ++j) {
+        for (uint8_t j = 0; j < (uint8_t) share_length; ++j) {
             secret[j] = shares[0][j];
         }
         return share_length;