diff --git a/gen/llvmhelpers.cpp b/gen/llvmhelpers.cpp
index 46047b6b..d9520934 100644
--- a/gen/llvmhelpers.cpp
+++ b/gen/llvmhelpers.cpp
@@ -380,7 +380,14 @@ void DtoAssign(Loc& loc, DValue* lhs, DValue* rhs, int op, bool canSkipPostblit)
     }
 
     if (t->ty == Tstruct) {
-        DtoAggrCopy(lhs->getLVal(), rhs->getRVal());
+        llvm::Value* src = rhs->getRVal();
+        llvm::Value* dst = lhs->getLVal();
+
+        // Check whether source and destination values are the same at compile
+        // time as to not emit an invalid (overlapping) memcpy on trivial
+        // struct self-assignments like 'A a; a = a;'.
+        if (src != dst)
+            DtoAggrCopy(dst, src);
     }
     else if (t->ty == Tarray) {
         // lhs is slice