diff --git a/src/lpython/parser/parser.cpp b/src/lpython/parser/parser.cpp
index f5bbf0408e..a5991564d6 100644
--- a/src/lpython/parser/parser.cpp
+++ b/src/lpython/parser/parser.cpp
@@ -113,36 +113,21 @@ std::string unique_filename(const std::string &prefix) {
 }
 
 Result<LPython::AST::ast_t*> parse_python_file(Allocator &al,
-        const std::string &runtime_library_dir,
+        const std::string &/*runtime_library_dir*/,
         const std::string &infile,
         diag::Diagnostics &diagnostics,
         bool new_parser) {
     LPython::AST::ast_t* ast;
-    if (new_parser) {
-        std::string input = read_file(infile);
-        Result<LPython::AST::Module_t*> res = parse(al, input, diagnostics);
-        if (res.ok) {
-            ast = (LPython::AST::ast_t*)res.result;
-        } else {
-            LFORTRAN_ASSERT(diagnostics.has_error())
-            return Error();
-        }
+    // We will be using the new parser from now on
+    new_parser = true;
+    LFORTRAN_ASSERT(new_parser)
+    std::string input = read_file(infile);
+    Result<LPython::AST::Module_t*> res = parse(al, input, diagnostics);
+    if (res.ok) {
+        ast = (LPython::AST::ast_t*)res.result;
     } else {
-        std::string outfile = unique_filename(infile);
-        std::string pycmd = "python " + runtime_library_dir
-            + "/lpython_parser.py " + infile + " " + outfile;
-        int err = std::system(pycmd.c_str());
-        if (err != 0) {
-            std::cerr << "The command '" << pycmd << "' failed." << std::endl;
-            return Error();
-        }
-        std::string input;
-        bool status = read_file(outfile, input);
-        if (!status) {
-            std::cerr << "The file '" << outfile << "' cannot be read." << std::endl;
-            return Error();
-        }
-        ast = LPython::deserialize_ast(al, input);
+        LFORTRAN_ASSERT(diagnostics.has_error())
+        return Error();
     }
     return ast;
 }
diff --git a/src/lpython/parser/parser.yy b/src/lpython/parser/parser.yy
index 99c9f3bd86..c61b84be4e 100644
--- a/src/lpython/parser/parser.yy
+++ b/src/lpython/parser/parser.yy
@@ -315,12 +315,12 @@ script_unit
     ;
 
 statements
-    : TK_INDENT statements1 TK_DEDENT { $$ = $2; }
+    : TK_INDENT statements1 TK_DEDENT { FLOC(@$, @2); LLOC(@$,@2); $$ = $2; }
     ;
 
 sep_statements
-    : sep statements { $$ = $2; }
-    | type_ignore_sep statements { $$ = $2; }
+    : sep statements { FLOC(@$, @2); $$ = $2; }
+    | type_ignore_sep statements { FLOC(@$, @2); $$ = $2; }
     ;
 
 body_stmts
@@ -334,9 +334,9 @@ statements1
     ;
 
 single_line_statements
-    : single_line_multi_statements TK_NEWLINE { $$ = $1; }
+    : single_line_multi_statements TK_NEWLINE { LLOC(@$,@1); $$ = $1; }
     | single_line_multi_statements TK_EOLCOMMENT { $$ = $1; }
-    | single_line_statement TK_NEWLINE { $$ = A2LIST(p.m_a, $1); }
+    | single_line_statement TK_NEWLINE { LLOC(@$,@1); $$ = A2LIST(p.m_a, $1); }
     | single_line_statement TK_SEMICOLON TK_NEWLINE { $$ = A2LIST(p.m_a, $1); }
     | single_line_statement TK_SEMICOLON TK_EOLCOMMENT { $$ = A2LIST(p.m_a, $1); }
     | single_line_statement TK_EOLCOMMENT { $$ = A2LIST(p.m_a, $1); }
@@ -358,10 +358,10 @@ type_ignore_sep
     ;
 
 statement
-    : single_line_statement sep { $$ = $1; }
+    : single_line_statement sep { LLOC(@$,@1); $$ = $1; }
     | single_line_statement type_ignore_sep { $$ = $1; }
     | multi_line_statement
-    | multi_line_statement sep { $$ = $1; }
+    | multi_line_statement sep { LLOC(@$,@1); $$ = $1; }
     | multi_line_statement type_ignore_sep { $$ = $1; }
     ;
 
@@ -698,28 +698,28 @@ comma_opt
 
 function_def
     : decorators_opt KW_DEF id "(" parameter_list_opt ")" ":"
-        body_stmts { $$ = FUNCTION_01($1, $3, $5, $8, @$); }
+        body_stmts { FLOC(@$, @2); $$ = FUNCTION_01($1, $3, $5, $8, @$); }
     | decorators_opt KW_DEF id "(" parameter_list_opt ")" "->" expr ":"
-        body_stmts { $$ = FUNCTION_02($1, $3, $5, $8, $10, @$); }
+        body_stmts { FLOC(@$, @2); $$ = FUNCTION_02($1, $3, $5, $8, $10, @$); }
     | decorators_opt KW_DEF id "(" parameter_list_opt ")" ":"
         TK_TYPE_COMMENT sep statements {
-        $$ = FUNCTION_03($1, $3, $5, $10, $8, @$); }
+        FLOC(@$, @2); $$ = FUNCTION_03($1, $3, $5, $10, $8, @$); }
     | decorators_opt KW_DEF id "(" parameter_list_opt ")" "->" expr ":"
         TK_TYPE_COMMENT sep statements {
-            $$ = FUNCTION_04($1, $3, $5, $8, $12, $10, @$); }
+            FLOC(@$, @2); $$ = FUNCTION_04($1, $3, $5, $8, $12, $10, @$); }
     | decorators_opt KW_DEF id "(" parameter_list_opt ")" ":"
         sep TK_TYPE_COMMENT sep statements {
-        $$ = FUNCTION_03($1, $3, $5, $11, $9, @$); }
+        FLOC(@$, @2); $$ = FUNCTION_03($1, $3, $5, $11, $9, @$); }
     | decorators_opt KW_DEF id "(" parameter_list_opt ")" "->" expr ":"
         sep TK_TYPE_COMMENT sep statements {
-            $$ = FUNCTION_04($1, $3, $5, $8, $13, $11, @$); }
+            FLOC(@$, @2); $$ = FUNCTION_04($1, $3, $5, $8, $13, $11, @$); }
     ;
 
 class_def
     : decorators_opt KW_CLASS id ":" body_stmts {
-        $$ = CLASS_01($1, $3, $5, @$); }
+       FLOC(@$, @2); $$ = CLASS_01($1, $3, $5, @$); }
     | decorators_opt KW_CLASS id "(" call_arguement_list ")" ":" body_stmts {
-        $$ = CLASS_02($1, $3, $5, $8, @$); }
+       FLOC(@$, @2); $$ = CLASS_02($1, $3, $5, $8, @$); }
     ;
 
 async_func_def
diff --git a/src/lpython/parser/semantics.h b/src/lpython/parser/semantics.h
index 5311b930f9..8fcc8e06e6 100644
--- a/src/lpython/parser/semantics.h
+++ b/src/lpython/parser/semantics.h
@@ -58,6 +58,11 @@ static inline T** vec_cast(const Vec<ast_t*> &x) {
     return s;
 }
 
+// Assign first/last location to `a` from `b`
+#define FLOC(a, b) a.first = b.first;
+#define LLOC(a, b) a.last = b.last;
+
+
 #define VEC_CAST(x, type) vec_cast<type##_t, astType::type>(x)
 #define STMTS(x) VEC_CAST(x, stmt)
 #define EXPRS(x) VEC_CAST(x, expr)