diff --git a/apps/apps_container.cpp b/apps/apps_container.cpp
index 4c15fdfb6..f8fea9c26 100644
--- a/apps/apps_container.cpp
+++ b/apps/apps_container.cpp
@@ -1,6 +1,7 @@
 #include "apps_container.h"
 #include "global_preferences.h"
 #include <ion.h>
+#include <poincare/tree_pool.h>
 
 extern "C" {
 #include <assert.h>
@@ -82,8 +83,18 @@ void AppsContainer::suspend(bool checkIfPowerKeyReleased) {
 }
 
 bool AppsContainer::dispatchEvent(Ion::Events::Event event) {
-  bool alphaLockWantsRedraw = updateAlphaLock();
+  jmp_buf jumpEnvironment;
+  Poincare::TreePool::sharedPool()->setJumpEnvironment(&jumpEnvironment);
+  int res = setjmp(jumpEnvironment);
+  if (res != 0) {
+    // There has been an exception, return an uninitialized node
+    Poincare::TreePool::sharedPool()->resetJumpEnvironment();// TODO Needed?
+    switchTo(appSnapshotAtIndex(0));
+    //displayMemoryExhaustionPopUp(); TODO
+    return true;
+  }
 
+  bool alphaLockWantsRedraw = updateAlphaLock();
   bool didProcessEvent = false;
 
   if (event == Ion::Events::USBEnumeration) {
@@ -114,8 +125,10 @@ bool AppsContainer::dispatchEvent(Ion::Events::Event event) {
   }
   if (!didProcessEvent && alphaLockWantsRedraw) {
     window()->redraw();
+    Poincare::TreePool::sharedPool()->resetJumpEnvironment(); // TODO Needed?
     return true;
   }
+  Poincare::TreePool::sharedPool()->resetJumpEnvironment(); // TODO Needed?
   return didProcessEvent || alphaLockWantsRedraw;
 }
 
diff --git a/escher/src/container.cpp b/escher/src/container.cpp
index 0b918de86..4ca3c0357 100644
--- a/escher/src/container.cpp
+++ b/escher/src/container.cpp
@@ -1,5 +1,6 @@
 #include <escher/container.h>
 #include <assert.h>
+#include <setjmp.h>
 
 Container::Container() :
   RunLoop(),
@@ -36,7 +37,11 @@ App * Container::activeApp() {
 }
 
 bool Container::dispatchEvent(Ion::Events::Event event) {
-  if (event == Ion::Events::TimerFire || m_activeApp->processEvent(event)) {
+  if (event == Ion::Events::TimerFire ) {
+    window()->redraw();
+    return true;
+  }
+  if (m_activeApp->processEvent(event)) {
     window()->redraw();
     return true;
   }
diff --git a/poincare/include/poincare/expression.h b/poincare/include/poincare/expression.h
index b9ecdc9e5..0007287c2 100644
--- a/poincare/include/poincare/expression.h
+++ b/poincare/include/poincare/expression.h
@@ -160,25 +160,27 @@ public:
   bool isEqualToItsApproximationLayout(Expression approximation, int bufferSize, Preferences::AngleUnit angleUnit, Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits, Context & context);
 
   /* Layout Helper */
-  LayoutRef createLayout(Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const;
+  LayoutRef createLayout(Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const {
+    return node()->createLayout(floatDisplayMode, numberOfSignificantDigits);
+  }
   int serialize(char * buffer, int bufferSize, Preferences::PrintFloatMode floatDisplayMode = Preferences::PrintFloatMode::Decimal, int numberOfSignificantDigits = PrintFloat::k_numberOfStoredSignificantDigits) const { return this->node()->serialize(buffer, bufferSize, floatDisplayMode, numberOfSignificantDigits); }
 
   /* Simplification */
   static Expression ParseAndSimplify(const char * text, Context & context, Preferences::AngleUnit angleUnit);
   Expression simplify(Context & context, Preferences::AngleUnit angleUnit);
-  Expression deepReduce(Context & context, Preferences::AngleUnit angleUnit);
+  Expression deepReduce(Context & context, Preferences::AngleUnit angleUnit); //TODO put private
 
   /* Approximation Helper */
   template<typename U> static U epsilon();
   template<typename U> Evaluation<U> approximateToEvaluation(Context& context, Preferences::AngleUnit angleUnit) const {
-    return node()->approximate(U(), context, angleUnit);
+    return node()->approximate(U(), context, angleUnit); //TODO put private
   }
 
   template<typename U> Expression approximate(Context& context, Preferences::AngleUnit angleUnit, Preferences::ComplexFormat complexFormat) const;
   template<typename U> U approximateToScalar(Context& context, Preferences::AngleUnit angleUnit) const;
   template<typename U> static U approximateToScalar(const char * text, Context& context, Preferences::AngleUnit angleUnit);
   template<typename U> U approximateWithValueForSymbol(char symbol, U x, Context & context, Preferences::AngleUnit angleUnit) const;
-  /* Expression roots/extrema solver*/
+  /* Expression roots/extrema solver */
   struct Coordinate2D {
     double abscissa;
     double value;
diff --git a/poincare/src/expression.cpp b/poincare/src/expression.cpp
index 7ea4015aa..29d627936 100644
--- a/poincare/src/expression.cpp
+++ b/poincare/src/expression.cpp
@@ -9,7 +9,6 @@
 #include <ion.h>
 #include <cmath>
 #include <float.h>
-#include <setjmp.h>
 
 #include "expression_lexer_parser.h"
 #include "expression_parser.hpp"
@@ -28,19 +27,26 @@ Expression Expression::parse(char const * string) {
   if (string[0] == 0) {
     return Expression();
   }
-  YY_BUFFER_STATE buf = poincare_expression_yy_scan_string(string);
 
-  jmp_buf jumpEnvironment;
-  TreePool::sharedPool()->setJumpEnvironment(&jumpEnvironment);
-  int res = setjmp(jumpEnvironment);
-  if (res != 0) {
-    // There has been an exception, return an uninitialized node
-    TreePool::sharedPool()->resetJumpEnvironment();
-    poincare_expression_yylval.expression = Expression();
-    poincare_expression_yy_delete_buffer(buf);
-    return Expression();
-  }
-  Expression expression;
+  /* The lexer/parser mallocs memory that needs to be freed once the parsing
+   * finishes, even if the parsing was interrupted by a memory exhaustion
+   * exception. We thus create another setjmp/lngjmp routine here to catch
+   * exceptions, delete the malloced memory and restore the previous jump
+   * environment */
+   jmp_buf * previousJumpEnvironment = TreePool::sharedPool()->jumpEnvironment();
+   jmp_buf jumpEnvironment;
+   TreePool::sharedPool()->setJumpEnvironment(&jumpEnvironment);
+   int res = setjmp(jumpEnvironment);
+   if (res != 0) {
+     // There has been an exception. Delete malloced memory and jump.
+     poincare_expression_yylval.expression = Expression();
+     poincare_expression_yy_delete_buffer(buf);
+     TreePool::sharedPool()->resetJumpEnvironment();
+     longjmp(*previousJumpEnvironment, 1);
+   }
+   TreePool::sharedPool()->setJumpEnvironment(&jumpEnvironment);
+   int res = setjmp(jumpEnvironment); YY_BUFFER_STATE buf = poincare_expression_yy_scan_string(string);
+   Expression expression;
   if (poincare_expression_yyparse(&expression) != 0) {
     // Parsing failed because of invalid input or memory exhaustion
     expression = Expression();
@@ -49,7 +55,7 @@ Expression Expression::parse(char const * string) {
    * expression alive if only YYVAL refers to it so we reset YYVAL here. */
   poincare_expression_yylval.expression = Expression();
   poincare_expression_yy_delete_buffer(buf);
-  TreePool::sharedPool()->resetJumpEnvironment();
+  TreePool::sharedPool()->setJumpEnvironment(&previousJumpEnvironment);
   return expression;
 }
 
@@ -226,21 +232,6 @@ bool Expression::isEqualToItsApproximationLayout(Expression approximation, int b
   return equal;
 }
 
-LayoutRef Expression::createLayout(Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const {
-  jmp_buf jumpEnvironment;
-  TreePool::sharedPool()->setJumpEnvironment(&jumpEnvironment);
-  int res = setjmp(jumpEnvironment);
-  if (res != 0) {
-    assert(false);
-    // There has been an exception, return an uninitialized layout
-    TreePool::sharedPool()->resetJumpEnvironment();
-    return LayoutRef();
-  }
-  LayoutRef result = node()->createLayout(floatDisplayMode, numberOfSignificantDigits);
-  TreePool::sharedPool()->resetJumpEnvironment();
-  return result;
-}
-
 /* Simplification */
 
 Expression Expression::ParseAndSimplify(const char * text, Context & context, Preferences::AngleUnit angleUnit) {
@@ -293,13 +284,13 @@ Expression Expression::deepBeautify(Context & context, Preferences::AngleUnit an
 
 template<typename U>
 Expression Expression::approximate(Context& context, Preferences::AngleUnit angleUnit, Preferences::Preferences::ComplexFormat complexFormat) const {
-  Evaluation<U> e = node()->approximate(U(), context, angleUnit);
+  Evaluation<U> e = node()->approximate(U(), context, angleUnit); //TODO approximateToEval
   return e.complexToExpression(complexFormat);
 }
 
 template<typename U>
 U Expression::approximateToScalar(Context& context, Preferences::AngleUnit angleUnit) const {
-  Evaluation<U> evaluation = node()->approximate(U(), context, angleUnit);
+  Evaluation<U> evaluation = node()->approximate(U(), context, angleUnit);//TODO approximateToEval
   return evaluation.toScalar();
 }