diff --git a/composer.json b/composer.json
index b025e39..265c4d8 100644
--- a/composer.json
+++ b/composer.json
@@ -4,7 +4,7 @@
     "license": "Apache-2.0",
     "minimum-stability": "dev",
     "require": {
-        "php": ">=5.5",
+        "php": ">=5.4",
         "ext-json": "*"
     },
     "require-dev": {
diff --git a/src/L20n/Compiler/Expression/ComplexString.php b/src/L20n/Compiler/Expression/ComplexString.php
index 677cd28..c9f5f37 100644
--- a/src/L20n/Compiler/Expression/ComplexString.php
+++ b/src/L20n/Compiler/Expression/ComplexString.php
@@ -75,12 +75,13 @@ public function __invoke(Locals $locals, \stdClass $ctxdata = null, $prop = null
                 }
                 $parts[] = $part;
             }
+            $this->dirty = false;
         } catch (CompilerException $e) {
+            $this->dirty = false;
             throw new ValueException($e->getMessage());
         } catch (\Exception $e) {
-            throw $e;
-        } finally {
             $this->dirty = false;
+            throw $e;
         }
         return [$locals, implode('', $parts)];
     }
diff --git a/src/L20n/Compiler/Expression/IndexExpression.php b/src/L20n/Compiler/Expression/IndexExpression.php
index fbcd259..a0c6aa4 100644
--- a/src/L20n/Compiler/Expression/IndexExpression.php
+++ b/src/L20n/Compiler/Expression/IndexExpression.php
@@ -50,14 +50,16 @@ public function __invoke(Locals $locals, \stdClass $ctxdata = null, $prop = null
         $retval = null;
         try {
             $retval = Expression::_resolve($this->expression, $locals, $ctxdata);
+            $this->dirty = false;
         } catch (IndexException $e) {
+            $this->dirty = false;
             throw $e;
         } catch (CompilerException $e) {
+            $this->dirty = false;
             throw new IndexException($e->getMessage());
         } catch (\Exception $e) {
-            throw $e;
-        } finally {
             $this->dirty = false;
+            throw $e;
         }
         return [$locals, $retval];
     }