diff --git a/src/parser/FormulaParser.cpp b/src/parser/FormulaParser.cpp
index 318c110c2..2bf1c392d 100644
--- a/src/parser/FormulaParser.cpp
+++ b/src/parser/FormulaParser.cpp
@@ -17,6 +17,12 @@
 namespace storm {
     namespace parser {
         
+        
+        FormulaParser::FormulaParser() : manager(new storm::expressions::ExpressionManager()), grammar(new FormulaParserGrammar(manager)) {
+            // Intentionally left empty.
+        }
+
+        
         FormulaParser::FormulaParser(std::shared_ptr<storm::expressions::ExpressionManager const> const& manager) : manager(manager), grammar(new FormulaParserGrammar(manager)) {
             // Intentionally left empty.
         }
diff --git a/src/parser/FormulaParser.h b/src/parser/FormulaParser.h
index 3dcbb0292..6afacf173 100644
--- a/src/parser/FormulaParser.h
+++ b/src/parser/FormulaParser.h
@@ -21,8 +21,9 @@ namespace storm {
         
         class FormulaParser {
         public:
-            FormulaParser(std::shared_ptr<storm::expressions::ExpressionManager const> const& manager);
-            FormulaParser(storm::prism::Program const& program);
+            FormulaParser();
+            explicit FormulaParser(std::shared_ptr<storm::expressions::ExpressionManager const> const& manager);
+            explicit FormulaParser(storm::prism::Program const& program);
             
             FormulaParser(FormulaParser const& other);
             FormulaParser& operator=(FormulaParser const& other);
diff --git a/src/parser/PgclParser.cpp b/src/parser/PgclParser.cpp
index 4c3c840f5..e65ff912d 100755
--- a/src/parser/PgclParser.cpp
+++ b/src/parser/PgclParser.cpp
@@ -80,9 +80,9 @@ namespace storm {
 
             // Simple statements
             doubleDeclaration           = (qi::lit("double ") >> variableName)[qi::_val = phoenix::bind(&PgclParser::declareDoubleVariable, phoenix::ref(*this), qi::_1)];
-            integerDeclaration = (qi::lit("int ") >> variableName >> qi::lit(":=") >> expression >> qi::lit(";"))[qi::_val = phoenix::bind(&PgclParser::createIntegerDeclarationStatement, phoenix::ref(*this), qi::_1, qi::_2)];
+            integerDeclaration = (qi::lit("int ") > variableName > qi::lit(":=") > expression > qi::lit(";"))[qi::_val = phoenix::bind(&PgclParser::createIntegerDeclarationStatement, phoenix::ref(*this), qi::_1, qi::_2)];
             integerDeclaration.name("integer declaration");
-            booleanDeclaration = (qi::lit("bool ") >> variableName >> qi::lit(":=") >> expression >> qi::lit(";"))[qi::_val = phoenix::bind(&PgclParser::createBooleanDeclarationStatement, phoenix::ref(*this), qi::_1, qi::_2)];
+            booleanDeclaration = (qi::lit("bool ") > variableName > qi::lit(":=") > expression > qi::lit(";"))[qi::_val = phoenix::bind(&PgclParser::createBooleanDeclarationStatement, phoenix::ref(*this), qi::_1, qi::_2)];
             booleanDeclaration.name("boolean declaration");
             
             assignmentStatement         = (variableName > qi::lit(":=") > (expression | uniformExpression) > qi::lit(";"))[qi::_val = phoenix::bind(&PgclParser::createAssignmentStatement, phoenix::ref(*this), qi::_1, qi::_2)];
diff --git a/src/parser/PrismParser.h b/src/parser/PrismParser.h
index 3d10a6c6a..911dbe479 100644
--- a/src/parser/PrismParser.h
+++ b/src/parser/PrismParser.h
@@ -10,7 +10,6 @@
 #include "src/parser/SpiritErrorHandler.h"
 #include "src/storage/prism/Program.h"
 #include "src/storage/expressions/Expression.h"
-#include "src/storage/expressions/Expressions.h"
 
 namespace storm {
     namespace expressions {