diff --git a/doomsday/libs/core/include/de/data/block.h b/doomsday/libs/core/include/de/data/block.h
index 7d69f2f275..d90ab62413 100644
--- a/doomsday/libs/core/include/de/data/block.h
+++ b/doomsday/libs/core/include/de/data/block.h
@@ -127,6 +127,7 @@ class DE_PUBLIC Block
     Block &operator+=(const IByteArray &byteArray);
 
     Block &operator=(const Block &other);
+    Block &operator=(Block &&moved);
     Block &operator=(const IByteArray &byteArray);
 
     Block  compressed(int level = -1) const;
diff --git a/doomsday/libs/core/include/de/data/string.h b/doomsday/libs/core/include/de/data/string.h
index edf892f7d8..3fea0fde03 100644
--- a/doomsday/libs/core/include/de/data/string.h
+++ b/doomsday/libs/core/include/de/data/string.h
@@ -262,12 +262,7 @@ class DE_PUBLIC String : public IByteArray
 
     inline String &operator=(String &&moved)
     {
-        if (_str.chars.i)
-        {
-            deinit_String(&_str);
-        }
-        _str = moved._str;
-        zap(moved._str);
+        set_String(&_str, &moved._str);
         return *this;
     }
 
diff --git a/doomsday/libs/core/src/data/block.cpp b/doomsday/libs/core/src/data/block.cpp
index 91ed19c9ed..1b75fcefff 100644
--- a/doomsday/libs/core/src/data/block.cpp
+++ b/doomsday/libs/core/src/data/block.cpp
@@ -51,8 +51,7 @@ Block::Block(const Block &other)
 
 Block::Block(Block &&moved)
 {
-    _block = moved._block;
-    iZap(moved._block);
+    set_Block(&_block, &moved._block);
 }
 
 Block::Block(const char *nullTerminatedCStr)
@@ -274,10 +273,16 @@ Block &Block::operator+=(const IByteArray &byteArray)
 
 Block &Block::operator=(const Block &other)
 {
-    set_Block(&_block, other);
+    set_Block(&_block, &other._block);
     return *this;
 }
 
+Block &Block::operator=(Block &&moved)
+{
+    set_Block(&_block, &moved._block);
+    return *this;
+}
+    
 Block &Block::operator=(const IByteArray &byteArray)
 {
     copyFrom(byteArray, 0, byteArray.size());
diff --git a/doomsday/libs/core/src/data/string.cpp b/doomsday/libs/core/src/data/string.cpp
index 3da4f91bda..1baae65d96 100644
--- a/doomsday/libs/core/src/data/string.cpp
+++ b/doomsday/libs/core/src/data/string.cpp
@@ -1,7 +1,7 @@
 /*
  * The Doomsday Engine Project -- libcore
  *
- * Copyright © 2004-2017 Jaakko Keränen <jaakko.keranen@iki.fi>
+ * Copyright © 2004-2018 Jaakko Keränen <jaakko.keranen@iki.fi>
  *
  * @par License
  * LGPL: http://www.gnu.org/licenses/lgpl.html
@@ -46,8 +46,7 @@ String::String(const String &other)
 
 String::String(String &&moved)
 {
-    _str = moved._str;
-    iZap(moved._str);
+    initCopy_String(&_str, &moved._str);
 }
 
 String::String(const Block &bytes)