Index: uspace/lib/cpp/include/impl/string.hpp
===================================================================
--- uspace/lib/cpp/include/impl/string.hpp	(revision 999cb48e06b5198a645280ecd7dd3087b57942e0)
+++ uspace/lib/cpp/include/impl/string.hpp	(revision edd2e61784c2460eb30ab887f993419c0871bd89)
@@ -1484,5 +1484,5 @@
 
                 size_ = size;
-                capacity_ = size;
+                capacity_ = size + 1;
 
                 data_ = allocator_.allocate(capacity_);