diff --git a/src/baseN.cpp b/src/baseN.cpp
index 8308744..c291e4a 100644
--- a/src/baseN.cpp
+++ b/src/baseN.cpp
@@ -41,7 +41,7 @@ namespace baseN
             idx_str = enc_size - 1;
         uint16_t div = data[idx_div++];
 
-        while (data[zero_count] == 0)
+        while (zero_count < (int64_t)data_size && data[zero_count] == 0)
         {
             zero_count++;
         }
@@ -113,7 +113,7 @@ namespace baseN
             idx_quo_last = dec_size - 2;
         uint16_t div;
 
-        while (str[zero_count] == digits[0])
+        while (str[zero_count] != '\0' && str[zero_count] == digits[0])
         {
             zero_count++;
         }
diff --git a/test/test-baseN.cpp b/test/test-baseN.cpp
index a73add7..1b081d4 100644
--- a/test/test-baseN.cpp
+++ b/test/test-baseN.cpp
@@ -39,10 +39,10 @@ TEST(baseN, encode)
     EXPECT_EQ("KyKXa", encode(hex::decode("0ccbd755"), 58, b58digits));
     EXPECT_EQ("KyKXaa", encode(hex::decode("02e62ec963"), 58, b58digits));
 }
-// TEST(baseN, encode_1e6)
+// TEST(baseN, encode_1e3)
 // {
-//     std::vector<uint8_t> data(1e6);
-//     encode(data);
+//     std::vector<uint8_t> data(1e3);
+//     encode(data, 58, b58digits, data.size() * 138 / 100 + 1);
 // }
 TEST(baseN, decode)
 {
@@ -52,10 +52,10 @@ TEST(baseN, decode)
     EXPECT_EQ(hex::encode(decode("KyKXa", 58, b58digits, b58map)), "0ccbd755");
     EXPECT_EQ(hex::encode(decode("KyKXaa", 58, b58digits, b58map)), "02e62ec963");
 }
-// TEST(baseN, decode_1e6)
+// TEST(baseN, decode_1e4)
 // {
-//     std::string str(1e6, '0');
-//     decode(str);
+//     std::string str(1e4, '1');
+//     decode(str, 58, b58digits, b58map, str.size() * 733 / 1000 + 1);
 // }
 
 int main(int argc, char **argv)