diff --git a/src/futils.cpp b/src/futils.cpp
index 468f4ab0..680e72d8 100644
--- a/src/futils.cpp
+++ b/src/futils.cpp
@@ -155,13 +155,11 @@ namespace Exiv2 {
         int   rc = result && data_buf && output_length < resultSize ? 1 : 0;
         if (  rc ) {
             const unsigned char* data = (const unsigned char*) data_buf ;
-            ::memset(result,0,resultSize);
-
             for (size_t i = 0, j = 0 ; i < dataLength;) {
 
-                uint32_t octet_a = data[i++] ;
-                uint32_t octet_b = data[i++] ;
-                uint32_t octet_c = data[i++] ;
+                uint32_t octet_a = i < dataLength ? data[i++] : 0 ;
+                uint32_t octet_b = i < dataLength ? data[i++] : 0 ;
+                uint32_t octet_c = i < dataLength ? data[i++] : 0 ;
 
                 uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;