diff --git a/src/futils.cpp b/src/futils.cpp
index 9b8e3792..e24acbca 100644
--- a/src/futils.cpp
+++ b/src/futils.cpp
@@ -215,7 +215,7 @@ namespace Exiv2 {
                 if (j < output_length) out[j++] = (triple >> 1 * 8) & 0xFF;
                 if (j < output_length) out[j++] = (triple >> 0 * 8) & 0xFF;
             }
-            out[output_length++]=0;
+            out[output_length]=0;
             result = output_length;
         }
         
diff --git a/unitTests/test_futils.cpp b/unitTests/test_futils.cpp
index 25545fd1..46b21dd1 100644
--- a/unitTests/test_futils.cpp
+++ b/unitTests/test_futils.cpp
@@ -147,7 +147,7 @@ TEST(base64decode, decodesValidString)
     const std::string original ("VGhpcyBpcyBhIHVuaXQgdGVzdA==");
     const std::string expected ("This is a unit test");
     char * result = new char [original.size()];
-    ASSERT_EQ(static_cast<long>(expected.size()+1),
+    ASSERT_EQ(static_cast<long>(expected.size()),
               base64decode(original.c_str(), result, original.size()));
     ASSERT_STREQ(expected.c_str(), result);
     delete [] result;