diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index 362b2e3ff2..2660eab63a 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -8,15 +8,15 @@ import (
 	v.table
 )
 
-pub type Expr = InfixExpr | IfExpr | StringLiteral | IntegerLiteral | CharLiteral | 	
-FloatLiteral | Ident | CallExpr | BoolLiteral | StructInit | ArrayInit | SelectorExpr | PostfixExpr | 	
-AssignExpr | PrefixExpr | MethodCallExpr | IndexExpr | RangeExpr | MatchExpr | 	
-CastExpr | EnumVal | Assoc | SizeOf | None | MapInit | IfGuardExpr | ParExpr | OrExpr | 	
+pub type Expr = InfixExpr | IfExpr | StringLiteral | IntegerLiteral | CharLiteral |
+FloatLiteral | Ident | CallExpr | BoolLiteral | StructInit | ArrayInit | SelectorExpr | PostfixExpr |
+AssignExpr | PrefixExpr | MethodCallExpr | IndexExpr | RangeExpr | MatchExpr |
+CastExpr | EnumVal | Assoc | SizeOf | None | MapInit | IfGuardExpr | ParExpr | OrExpr |
 ConcatExpr | Type | AsCast
 
-pub type Stmt = VarDecl | GlobalDecl | FnDecl | Return | Module | Import | ExprStmt | 	
-ForStmt | StructDecl | ForCStmt | ForInStmt | CompIf | ConstDecl | Attr | BranchStmt | 	
-HashStmt | AssignStmt | EnumDecl | TypeDecl | DeferStmt | GotoLabel | GotoStmt | 	
+pub type Stmt = VarDecl | GlobalDecl | FnDecl | Return | Module | Import | ExprStmt |
+ForStmt | StructDecl | ForCStmt | ForInStmt | CompIf | ConstDecl | Attr | BranchStmt |
+HashStmt | AssignStmt | EnumDecl | TypeDecl | DeferStmt | GotoLabel | GotoStmt |
 LineComment | MultiLineComment | AssertStmt | UnsafeStmt
 // pub type Type = StructType | ArrayType
 // pub struct StructType {
@@ -278,8 +278,9 @@ pub:
 	op         token.Kind
 	pos        token.Position
 	left       Expr
-	left_type  table.Type
 	right      Expr
+	mut:
+	left_type  table.Type
 	right_type table.Type
 }
 
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index d23822c06e..dfca62f9fc 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -120,9 +120,10 @@ pub fn (c mut Checker) check_struct_init(struct_init ast.StructInit) table.Type
 	return struct_init.typ
 }
 
-pub fn (c mut Checker) infix_expr(infix_expr ast.InfixExpr) table.Type {
+pub fn (c mut Checker) infix_expr(infix_expr mut ast.InfixExpr) table.Type {
 	// println('checker: infix expr(op $infix_expr.op.str())')
 	left_type := c.expr(infix_expr.left)
+	infix_expr.left_type = left_type
 	c.expected_type = left_type
 	right_type := c.expr(infix_expr.right)
 	if !c.table.check(right_type, left_type) {
@@ -429,7 +430,7 @@ pub fn (c mut Checker) array_init(array_init mut ast.ArrayInit) table.Type {
 			else {
 				c.error('expecting `int` for fixed size', array_init.pos)
 			}
-		}
+	}
 		idx := c.table.find_or_register_array_fixed(array_init.elem_type, fixed_size, 1)
 		array_type := table.new_type(idx)
 		array_init.typ = array_type
@@ -569,7 +570,7 @@ pub fn (c mut Checker) expr(node ast.Expr) table.Type {
 			return c.index_expr(mut it)
 		}
 		ast.InfixExpr {
-			return c.infix_expr(it)
+			return c.infix_expr(mut it)
 		}
 		ast.IntegerLiteral {
 			return table.int_type
@@ -808,7 +809,7 @@ pub fn (c mut Checker) index_expr(node mut ast.IndexExpr) table.Type {
 		else {}
 	}
 	if !is_range {
-		node.container_type =  typ
+		node.container_type = typ
 		typ_sym := c.table.get_type_symbol(typ)
 		index_type := c.expr(node.index)
 		index_type_sym := c.table.get_type_symbol(index_type)
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index bfcff3582a..8eb9ae0cb2 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -476,15 +476,23 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.index_expr(it)
 		}
 		ast.InfixExpr {
-			g.expr(it.left)
-			// if it.op == .dot {
-			// println('!! dot')
-			// }
-			g.write(' $it.op.str() ')
-			g.expr(it.right)
-			// if typ.name != typ2.name {
-			// verror('bad types $typ.name $typ2.name')
+			// if it.left_type == table.string_type_idx {
+			// g.write('/*$it.left_type str*/')
 			// }
+			if it.op == .plus && it.left_type == table.string_type_idx {
+				g.write('string_add(')
+				g.expr(it.left)
+				g.write(', ')
+				g.expr(it.right)
+			}
+			else {
+				// if it.op == .dot {
+				// println('!! dot')
+				// }
+				g.expr(it.left)
+				g.write(' $it.op.str() ')
+				g.expr(it.right)
+			}
 		}
 		ast.IntegerLiteral {
 			g.write(it.val.str())
diff --git a/vlib/v/gen/tests/1.c b/vlib/v/gen/tests/1.c
index 300f6cc1f6..825c9a99c5 100644
--- a/vlib/v/gen/tests/1.c
+++ b/vlib/v/gen/tests/1.c
@@ -88,6 +88,8 @@ i < 10; i++) {
 	bool b2 = array_get(bools, 0) || true;
 	bool b3 = get_bool() || true;
 	int f = array_int_first(nums);
+	string d = tos3("d");
+	println(string_add(s + d));
 }
 
 void User_inc_age(User u, int n) {
diff --git a/vlib/v/gen/tests/1.vv b/vlib/v/gen/tests/1.vv
index 36d9190ab5..52e59279a9 100644
--- a/vlib/v/gen/tests/1.vv
+++ b/vlib/v/gen/tests/1.vv
@@ -78,6 +78,8 @@ fn foo(a int) {
 	b2 := bools[0] || true
 	b3 := get_bool() || true
 	f := nums.first()
+	d := 'd'
+	println(s + d)
 	//cloned = nums.clone()
 	//cloned1 := cloned[0]
 	//println(cloned1 == 1)
diff --git a/vlib/v/gen/tests/4.c b/vlib/v/gen/tests/4.c
index dffbee6898..dea218e977 100644
--- a/vlib/v/gen/tests/4.c
+++ b/vlib/v/gen/tests/4.c
@@ -18,9 +18,9 @@ multi_return_int_string mr_test();
 int testa();
 string testb(int a);
 int testc(int a);
-int Foo_testa(Foo f);
-int Foo_testb(Foo f);
-int Bar_testa(Bar b);
+int Foo_testa(Foo* f);
+int Foo_testb(Foo* f);
+int Bar_testa(Bar* b);
 
 int main() {
     Bar b = (Bar){
@@ -71,16 +71,16 @@ int testc(int a) {
     return a;
 }
 
-int Foo_testa(Foo f) {
+int Foo_testa(Foo* f) {
     int a = Foo_testb(f);
     a = 1;
     return 4;
 }
 
-int Foo_testb(Foo f) {
+int Foo_testb(Foo* f) {
     return 4;
 }
 
-int Bar_testa(Bar b) {
+int Bar_testa(Bar* b) {
     return 4;
 }