diff --git a/apps/code/python_text_area.cpp b/apps/code/python_text_area.cpp
index 5d45bf203..1ac729dd1 100644
--- a/apps/code/python_text_area.cpp
+++ b/apps/code/python_text_area.cpp
@@ -256,6 +256,7 @@ void PythonTextArea::addAutocompletion() {
 
   const char * autocompletionLocation = const_cast<char *>(cursorLocation());
   const char * textToInsert = nullptr;
+  int textToInsertLength = 0;
   CodePoint prevCodePoint = UTF8Helper::PreviousCodePoint(m_contentView.editedText(), autocompletionLocation);
   if (!UTF8Helper::CodePointIsEndOfWord(prevCodePoint)
       && UTF8Helper::CodePointIsEndOfWord(UTF8Helper::CodePointAtLocation(autocompletionLocation)))
@@ -267,11 +268,11 @@ void PythonTextArea::addAutocompletion() {
      * builtins, then in the imported modules/scripts. */
     VariableBoxController * varBox = m_contentView.pythonDelegate()->variableBoxController();
     const char * beginningOfWord = m_contentView.textToAutocomplete();
-    textToInsert = varBox->autocompletionForText(m_contentView.pythonDelegate()->menuController()->editedScriptIndex(), beginningOfWord);
+    textToInsert = varBox->autocompletionForText(m_contentView.pythonDelegate()->menuController()->editedScriptIndex(), beginningOfWord, &textToInsertLength);
   }
 
   // Try to insert the text (this might fail if the buffer is full)
-  if (textToInsert && m_contentView.insertTextAtLocation(textToInsert, const_cast<char *>(autocompletionLocation))) {
+  if (textToInsert && textToInsertLength > 0 && m_contentView.insertTextAtLocation(textToInsert, const_cast<char *>(autocompletionLocation), textToInsertLength)) {
     m_contentView.setAutocompleting(true);
   }
 }
diff --git a/apps/code/variable_box_controller.cpp b/apps/code/variable_box_controller.cpp
index ce569135e..da723264b 100644
--- a/apps/code/variable_box_controller.cpp
+++ b/apps/code/variable_box_controller.cpp
@@ -331,7 +331,7 @@ void VariableBoxController::loadFunctionsAndVariables(int scriptIndex, const cha
 #endif
 }
 
-const char * VariableBoxController::autocompletionForText(int scriptIndex, const char * text) {
+const char * VariableBoxController::autocompletionForText(int scriptIndex, const char * text, int * textToInsertLength) {
   // TODO LEA Accelerate
   loadFunctionsAndVariables(scriptIndex, text);
   const char * endOfText = UTF8Helper::EndOfWord(text);
@@ -342,6 +342,7 @@ const char * VariableBoxController::autocompletionForText(int scriptIndex, const
     const char * currentName = node->name();
     int currentNameLength = node->nameLength();
     if ((currentNameLength < 0 || currentNameLength != textLength) && strncmp(text, currentName, textLength) == 0) {
+      *textToInsertLength = currentNameLength - textLength;
       return currentName + textLength;
     }
   }
diff --git a/apps/code/variable_box_controller.h b/apps/code/variable_box_controller.h
index 14925510c..aa436dbb5 100644
--- a/apps/code/variable_box_controller.h
+++ b/apps/code/variable_box_controller.h
@@ -27,7 +27,7 @@ public:
 
   /* VariableBoxController */
   void loadFunctionsAndVariables(int scriptIndex, const char * textToAutocomplete);
-  const char * autocompletionForText(int scriptIndex, const char * text);
+  const char * autocompletionForText(int scriptIndex, const char * text, int * textToInsertLength);
 private:
   constexpr static int k_maxScriptObjectNameSize = 100;
   constexpr static int k_maxNumberOfDisplayedRows = 6; // 240/40
diff --git a/escher/include/escher/text_area.h b/escher/include/escher/text_area.h
index 7d7e58716..41c177a41 100644
--- a/escher/include/escher/text_area.h
+++ b/escher/include/escher/text_area.h
@@ -117,7 +117,7 @@ protected:
     const char * editedText() const override { return m_text.text(); }
     size_t editedTextLength() const override { return m_text.textLength(); }
     const Text * getText() const { return &m_text; }
-    bool insertTextAtLocation(const char * text, char * location) override;
+    bool insertTextAtLocation(const char * text, char * location, int textLength = -1) override;
     void moveCursorGeo(int deltaX, int deltaY);
     bool removePreviousGlyph() override;
     bool removeEndOfLine() override;
diff --git a/escher/include/escher/text_field.h b/escher/include/escher/text_field.h
index af995328c..b7394f2b5 100644
--- a/escher/include/escher/text_field.h
+++ b/escher/include/escher/text_field.h
@@ -74,7 +74,7 @@ protected:
     /* If the text to be appended is too long to be added without overflowing the
      * buffer, nothing is done (not even adding few letters from the text to reach
      * the maximum buffer capacity) and false is returned. */
-    bool insertTextAtLocation(const char * text, char * location) override;
+    bool insertTextAtLocation(const char * text, char * location, int textLength = -1) override;
     KDSize minimalSizeForOptimalDisplay() const override;
     bool removePreviousGlyph() override;
     bool removeEndOfLine() override;
diff --git a/escher/include/escher/text_input.h b/escher/include/escher/text_input.h
index 82bb60106..34c75dcd8 100644
--- a/escher/include/escher/text_input.h
+++ b/escher/include/escher/text_input.h
@@ -49,7 +49,7 @@ protected:
 
     // Virtual text get/add/remove
     virtual const char * text() const = 0;
-    virtual bool insertTextAtLocation(const char * text, char * location) = 0;
+    virtual bool insertTextAtLocation(const char * text, char * location, int textLength = -1) = 0;
     virtual bool removePreviousGlyph() = 0;
     virtual bool removeEndOfLine() = 0;
 
diff --git a/escher/src/text_area.cpp b/escher/src/text_area.cpp
index 11dfc4045..8d4239df8 100644
--- a/escher/src/text_area.cpp
+++ b/escher/src/text_area.cpp
@@ -458,26 +458,19 @@ void TextArea::ContentView::setText(char * textBuffer, size_t textBufferSize) {
   m_cursorLocation = text();
 }
 
-bool TextArea::ContentView::insertTextAtLocation(const char * text, char * location) {
-  int textSize = strlen(text);
-  if (m_text.textLength() + textSize >= m_text.bufferSize() || textSize == 0) {
+bool TextArea::ContentView::insertTextAtLocation(const char * text, char * location, int textLength) {
+  int textLen = textLength < 0 ? strlen(text) : textLength;
+  assert(textLen < 0 || textLen <= strlen(text));
+  if (m_text.textLength() + textLen >= m_text.bufferSize() || textLen == 0) {
     return false;
   }
-  bool lineBreak = false;
 
-  // Scan for \n and 0
-  const char * nullLocation = UTF8Helper::PerformAtCodePoints(
-      text, '\n',
-      [](int codePointOffset, void * lineBreak, int context1, int context2) {
-        *((bool *)lineBreak) = true;
-      },
-      [](int c1, void * c2, int c3, int c4) { },
-      &lineBreak, 0);
+  // Scan for \n
+  bool lineBreak = UTF8Helper::HasCodePoint(text, '\n', text + textLen);
 
-  assert(UTF8Helper::CodePointIs(nullLocation, 0));
-  m_text.insertText(text, nullLocation - text, location);
+  m_text.insertText(text, textLen, location);
   // Replace System parentheses (used to keep layout tree structure) by normal parentheses
-  Poincare::SerializationHelper::ReplaceSystemParenthesesByUserParentheses(location, nullLocation - text);
+  Poincare::SerializationHelper::ReplaceSystemParenthesesByUserParentheses(location, textLen);
   reloadRectFromPosition(location, lineBreak);
   return true;
 }
diff --git a/escher/src/text_field.cpp b/escher/src/text_field.cpp
index bbabf8756..ebd9bd48a 100644
--- a/escher/src/text_field.cpp
+++ b/escher/src/text_field.cpp
@@ -119,10 +119,10 @@ void TextField::ContentView::reinitDraftTextBuffer() {
   setCursorLocation(s_draftTextBuffer);
 }
 
-bool TextField::ContentView::insertTextAtLocation(const char * text, char * location) {
+bool TextField::ContentView::insertTextAtLocation(const char * text, char * location, int textLen) {
   assert(m_isEditing);
 
-  int textLength = strlen(text);
+  int textLength = textLen < 0 ? strlen(text) : textLen;
   if (m_currentDraftTextLength + textLength >= m_draftTextBufferSize || textLength == 0) {
     return false;
   }
@@ -130,12 +130,12 @@ bool TextField::ContentView::insertTextAtLocation(const char * text, char * loca
   memmove(location + textLength, location, (s_draftTextBuffer + m_currentDraftTextLength + 1) - location);
 
   // Caution! One byte will be overridden by the null-terminating char of strlcpy
-  char * overridenByteLocation = location + textLength;
+  size_t copySize = std::min(textLength, (s_draftTextBuffer + m_draftTextBufferSize) - location);
+  char * overridenByteLocation = location + copySize;
   char overridenByte = *overridenByteLocation;
-  strlcpy(location, text, (s_draftTextBuffer + m_draftTextBufferSize) - location);
-  assert(overridenByteLocation < s_draftTextBuffer + m_draftTextBufferSize);
+  strlcpy(location, text, copySize);
   *overridenByteLocation = overridenByte;
-  m_currentDraftTextLength += textLength;
+  m_currentDraftTextLength += copySize;
 
   reloadRectFromPosition(m_horizontalAlignment == 0.0f ? location : s_draftTextBuffer);
   return true;
diff --git a/ion/include/ion/unicode/utf8_helper.h b/ion/include/ion/unicode/utf8_helper.h
index 38878989c..17ff9385f 100644
--- a/ion/include/ion/unicode/utf8_helper.h
+++ b/ion/include/ion/unicode/utf8_helper.h
@@ -11,10 +11,10 @@ int CountOccurrences(const char * s, CodePoint c);
 
 /* Returns the first occurence of a code point in a string, the position of the
  * null terminating char otherwise. */
-const char * CodePointSearch(const char * s, CodePoint c);
+const char * CodePointSearch(const char * s, CodePoint c, const char * stoppingPosition = nullptr);
 
 // Returns true if the text had the code point
-bool HasCodePoint(const char * s, CodePoint c);
+bool HasCodePoint(const char * s, CodePoint c, const char * stoppingPosition = nullptr);
 
 /* Returns the first occurence of a code point that is not c in a string,
  * stopping at the null-terminating char or the start of string. */
diff --git a/ion/src/shared/unicode/utf8_helper.cpp b/ion/src/shared/unicode/utf8_helper.cpp
index 6f2d3e41e..d15c897c6 100644
--- a/ion/src/shared/unicode/utf8_helper.cpp
+++ b/ion/src/shared/unicode/utf8_helper.cpp
@@ -33,10 +33,10 @@ int CountOccurrences(const char * s, CodePoint c) {
   return count;
 }
 
-const char * CodePointSearch(const char * s, CodePoint c) {
+const char * CodePointSearch(const char * s, CodePoint c, const char * stoppingPosition) {
   if (UTF8Decoder::CharSizeOfCodePoint(c) == 1) {
     const char * result = s;
-    while (*result != 0 && *result != c) {
+    while (*result != 0 && *result != c && (stoppingPosition == nullptr || result != stoppingPosition)) {
       result++;
     }
     return result;
@@ -45,7 +45,7 @@ const char * CodePointSearch(const char * s, CodePoint c) {
   const char * currentPointer = s;
   CodePoint codePoint = decoder.nextCodePoint();
   const char * nextPointer = decoder.stringPosition();
-  while (codePoint != UCodePointNull && codePoint != c) {
+  while (codePoint != UCodePointNull && codePoint != c && (stoppingPosition == nullptr || currentPointer < stoppingPosition)) {
     currentPointer = nextPointer;
     codePoint = decoder.nextCodePoint();
     nextPointer = decoder.stringPosition();
@@ -53,9 +53,10 @@ const char * CodePointSearch(const char * s, CodePoint c) {
   return currentPointer;
 }
 
-bool HasCodePoint(const char * s, CodePoint c) {
+bool HasCodePoint(const char * s, CodePoint c, const char * stoppingPosition) {
   assert(c != 0);
-  return *CodePointSearch(s, c) != 0;
+  const char * resultPosition = CodePointSearch(s, c, stoppingPosition);
+  return *resultPosition != 0 && (stoppingPosition == nullptr || resultPosition < stoppingPosition);
 }
 
 const char * NotCodePointSearch(const char * s, CodePoint c, bool goingLeft, const char * initialPosition) {