diff --git a/ast.cpp b/ast.cpp
index 087d7e8..3cd6771 100644
--- a/ast.cpp
+++ b/ast.cpp
@@ -510,8 +510,8 @@ ast_module_namespace(Token *pos, Ast_Module *module, Intern_String name){
 }
 
 function Ast_Module *
-ast_module(Intern_String filename){
-  AST_NEW(Module, MODULE, 0, 0);
+ast_module(Token *pos, Intern_String filename){
+  AST_NEW(Module, MODULE, pos, 0);
   result->parent_scope = 0;
   result->kind = AST_MODULE;
   result->name  = filename;
diff --git a/ccodegen.cpp b/ccodegen.cpp
index 369cc1e..aaa144f 100644
--- a/ccodegen.cpp
+++ b/ccodegen.cpp
@@ -597,11 +597,13 @@ gen_ast(Ast *ast){
 
 function void
 parse_file(Ast_File *file){
+  assert(file);
+
   Scratch scratch;
   file->filecontent = os_read_file(pctx->perm, file->filename.s);
-  assert(file);
-  assert(file->filecontent.len);
-  assert(file->filename.len);
+  if(file->filecontent.len == 0){
+    compiler_error(file->pos, "Failed to open file \"%Q\"", file->filename);
+  }
 
 
   pctx->currently_parsed_file  = file;
@@ -685,7 +687,7 @@ parse_all_modules(){
 }
 
 function Ast_Module *
-add_module(Intern_String filename){
+add_module(Token *pos, Intern_String filename){
   For(pctx->modules){
     if(it->name == filename){
       log_info("Returning registered module: %Q\n", filename);
@@ -694,8 +696,8 @@ add_module(Intern_String filename){
   }
 
   log_info("Adding module: %Q\n", filename);
-  Ast_Module *result = ast_module(filename);
-  register_ast_file(result->name, result, true);
+  Ast_Module *result = ast_module(pos, filename);
+  register_ast_file(pos, result->name, result, true);
   pctx->modules.add(result);
   return result;
 }
diff --git a/compiler.h b/compiler.h
index 796a5d5..48237e5 100644
--- a/compiler.h
+++ b/compiler.h
@@ -4,7 +4,7 @@ struct Ast_File_Namespace;
 struct Ast_File;
 struct Ast_Module;
 struct Ast_Type;
-function Ast_Module *ast_module(Intern_String filename);
+function Ast_Module *ast_module(Token *pos, Intern_String filename);
 function void insert_builtin_types_into_scope(Ast_Scope *p);
 
 enum Token_Kind{
@@ -246,7 +246,7 @@ parse_init(Parse_Ctx *ctx, Allocator *perm_allocator, Allocator *heap_allocator)
   arena_init(&ctx->stage_arena, "Compiler stage arena"_s);
 
   lex_init(ctx->perm, ctx->heap, ctx);
-  ctx->builtins = ast_module(ctx->intern("builtins"_s));
+  ctx->builtins = ast_module(0, ctx->intern("builtins"_s));
   insert_builtin_types_into_scope((Ast_Scope *)ctx->builtins);
 
   init_type();
diff --git a/main.cpp b/main.cpp
index b4f25e7..498107c 100644
--- a/main.cpp
+++ b/main.cpp
@@ -176,8 +176,8 @@ int main(int argument_count, char **arguments){
 
   F64 total_time = os_time();
   begin_compilation();
-  
-  Ast_Module *module = add_module(pctx->intern(program_name));
+
+  Ast_Module *module = add_module(0, pctx->intern(program_name));
   parse_all_modules();
   assert(module);
   resolve_everything_in_module(module);
diff --git a/parsing.cpp b/parsing.cpp
index 9bf9003..baf4413 100644
--- a/parsing.cpp
+++ b/parsing.cpp
@@ -671,7 +671,7 @@ add_implicit_import(Ast_Scope *scope, Ast_Scope *add){
 }
 
 function Ast_File *
-register_ast_file(Intern_String filename, Ast_Module *module, B32 global_implicit_load){
+register_ast_file(Token *pos, Intern_String filename, Ast_Module *module, B32 global_implicit_load){
   Ast_File *file = 0;
   For(module->all_loaded_files){
     if(it->filename == filename){
@@ -691,6 +691,7 @@ register_ast_file(Intern_String filename, Ast_Module *module, B32 global_implici
     file->decls          = {pctx->heap};
     file->implicit_imports = {pctx->heap};
     file->module->all_loaded_files.add(file);
+    file->pos = pos;
   }
 
   if(global_implicit_load) {
@@ -703,15 +704,15 @@ register_ast_file(Intern_String filename, Ast_Module *module, B32 global_implici
 function Ast_File *
 parse_load(B32 global_implicit_load){
   Token *file = token_expect(TK_StringLit);
-  Ast_File *result = register_ast_file(file->intern_val, pctx->currently_parsed_file->module, global_implicit_load);
+  Ast_File *result = register_ast_file(file, file->intern_val, pctx->currently_parsed_file->module, global_implicit_load);
   return result;
 }
 
-function Ast_Module *add_module(Intern_String filename);
+function Ast_Module *add_module(Token *pos, Intern_String filename);
 function Ast_Module *
 parse_import(B32 global_implicit_import){
   Token *file = token_expect(TK_StringLit);
-  Ast_Module *result = add_module(file->intern_val);
+  Ast_Module *result = add_module(file, file->intern_val);
   if(global_implicit_import){
     add_implicit_import(pctx->currently_parsed_file->module, result);
   }