diff --git a/base64.cpp b/base64.cpp
index 715e11aa..cc0c7c21 100644
--- a/base64.cpp
+++ b/base64.cpp
@@ -133,7 +133,7 @@ namespace data
         while ( *ps-- == P64 ) outCount--;
         ps = (unsigned char *)InBuffer;
         
-        if (outCount > len) return -1;
+        if (outCount > len) return 0;
         pd = OutBuffer;
         auto endOfOutBuffer = OutBuffer + outCount;     
         for ( i = 0; i < n; i++ ){
diff --git a/base64.h b/base64.h
index 938d82a8..3c1ecb76 100644
--- a/base64.h
+++ b/base64.h
@@ -17,6 +17,7 @@ namespace data
      * @param InCount length of the input array
      * @param OutBuffer array to store output characters 
      * @param len length of the output buffer
+     * @note zero is returned when the output buffer is too small 
      */
     size_t ByteStreamToBase64 (const uint8_t * InBuffer, size_t InCount, char * OutBuffer, size_t len);
 
@@ -28,6 +29,7 @@ namespace data
      * @param OutBuffer array to store output bytes
      * @param len length of the output buffer
      * @todo Do not return a negative value on failure, size_t could be unsigned.
+     * @note zero is returned when the output buffer is too small 
      */
     size_t Base64ToByteStream (const char * InBuffer, size_t InCount, uint8_t * OutBuffer, size_t len );
 
@@ -40,6 +42,7 @@ namespace data
      * @param len length of the input buffer
      * @param outBuf array to store output bytes
      * @param outLen length of the output array 
+     * @note zero is returned when the output buffer is too small 
      */
     size_t Base32ToByteStream (const char * inBuf, size_t len, uint8_t * outBuf, size_t outLen);
 
@@ -50,6 +53,7 @@ namespace data
      * @param len length of the input buffer
      * @param outBuf array to store output characters
      * @param outLen length of the output array 
+     * @note zero is returned when the output buffer is too small 
      */
     size_t ByteStreamToBase32 (const uint8_t * inBuf, size_t len, char * outBuf, size_t outLen);
 }