diff --git a/src/string.cc b/src/string.cc
index 42f3d7ce5..638eabdbf 100644
--- a/src/string.cc
+++ b/src/string.cc
@@ -114,6 +114,21 @@ void String::Data::release()
         Alloc{}.deallocate(l.ptr, l.capacity+1);
 }
 
+void String::resize(ByteCount size, char c)
+{
+    const size_t target_size = (size_t)size;
+    const size_t current_size = m_data.size();
+    if (target_size < current_size)
+        m_data.set_size(target_size);
+    else if (target_size > current_size)
+    {
+        m_data.reserve(target_size);
+        m_data.set_size(target_size);
+        for (auto i = current_size; i < target_size; ++i)
+            m_data.data()[i] = c;
+    }
+}
+
 void String::Data::set_size(size_t size)
 {
     if (is_long())
diff --git a/src/string.hh b/src/string.hh
index 390eacf1f..fb48137ed 100644
--- a/src/string.hh
+++ b/src/string.hh
@@ -125,6 +125,7 @@ public:
     void push_back(char c) { m_data.append(&c, 1); }
     void force_size(ByteCount size) { m_data.force_size((size_t)size); }
     void reserve(ByteCount size) { m_data.reserve((size_t)size); }
+    void resize(ByteCount size, char c);
 
     static const String ms_empty;
 
@@ -165,6 +166,7 @@ public:
 
 	template<bool copy = true>
         void reserve(size_t new_capacity);
+        void set_size(size_t size);
         void force_size(size_t new_size);
         void append(const char* str, size_t len);
         void clear();
@@ -172,7 +174,6 @@ public:
     private:
         void release();
         void set_empty() { s.size = 1; }
-        void set_size(size_t size);
         void set_short(const char* data, size_t size);
     };