diff --git a/Source/Core/InputCommon/ControlReference/ExpressionParser.cpp b/Source/Core/InputCommon/ControlReference/ExpressionParser.cpp
index 7e8e54b1ec..00afc5e036 100644
--- a/Source/Core/InputCommon/ControlReference/ExpressionParser.cpp
+++ b/Source/Core/InputCommon/ControlReference/ExpressionParser.cpp
@@ -34,7 +34,7 @@ bool Token::IsBinaryOperator() const
   return type >= TOK_BINARY_OPS_BEGIN && type < TOK_BINARY_OPS_END;
 }
 
-Lexer::Lexer(const std::string& expr_) : expr(expr_)
+Lexer::Lexer(std::string expr_) : expr(std::move(expr_))
 {
   it = expr.begin();
 }
diff --git a/Source/Core/InputCommon/ControlReference/ExpressionParser.h b/Source/Core/InputCommon/ControlReference/ExpressionParser.h
index 994f8c201b..cab6096c0e 100644
--- a/Source/Core/InputCommon/ControlReference/ExpressionParser.h
+++ b/Source/Core/InputCommon/ControlReference/ExpressionParser.h
@@ -71,7 +71,7 @@ public:
   std::string expr;
   std::string::iterator it;
 
-  Lexer(const std::string& expr_);
+  explicit Lexer(std::string expr_);
 
   ParseStatus Tokenize(std::vector<Token>& tokens);