diff --git a/cranelift-backend/src/lib.rs b/cranelift-backend/src/lib.rs
index 0d9418c..3c3002a 100644
--- a/cranelift-backend/src/lib.rs
+++ b/cranelift-backend/src/lib.rs
@@ -17,6 +17,7 @@ use {
         utils::{self as hbutils, Ent, EntVec},
     },
     std::{
+        collections::HashSet,
         fmt::{Display, Write},
         ops::Range,
     },
@@ -90,6 +91,9 @@ impl hblang::backend::Backend for Backend {
 
         self.globals.shadow(types.ins.globals.len());
 
+        #[cfg(debug_assertions)]
+        let mut seen_names = HashSet::new();
+
         self.asm.frontier.push(from.into());
         while let Some(itm) = self.asm.frontier.pop() {
             match itm.expand() {
@@ -156,6 +160,7 @@ impl hblang::backend::Backend for Backend {
                         &mut self.ctx.func.signature,
                         &mut vec![],
                     );
+                    debug_assert!(seen_names.insert(self.asm.name.clone()), "{}", self.asm.name);
                     fuc.module_id = Some(
                         module
                             .declare_function(&self.asm.name, linkage, &self.ctx.func.signature)
@@ -211,7 +216,9 @@ impl hblang::backend::Backend for Backend {
                     nm.index =
                         self.globals[hbty::Global::new(nm.index as _)].module_id.unwrap().as_u32();
                 }
+                let prev_len = self.ctx.func.params.user_named_funcs().len();
                 self.ctx.func.params.ensure_user_func_name(nm.clone());
+                debug_assert_ne!(self.ctx.func.params.user_named_funcs().len(), prev_len, "{}", nm);
             });
             module
                 .define_function_bytes(
@@ -254,7 +261,6 @@ impl hblang::backend::Backend for Backend {
         tys: &hbty::Types,
         files: &hbutils::EntSlice<hbty::Module, hblang::parser::Ast>,
     ) {
-        self.ctx.clear();
         let isa = self.module.as_ref().unwrap().isa();
 
         let mut lens = vec![];
@@ -286,6 +292,7 @@ impl hblang::backend::Backend for Backend {
         self.ctx.compile(isa, &mut self.ctrl_plane).unwrap();
         let code = self.ctx.compiled_code().unwrap();
         self.funcs.push(id, &self.ctx.func, &code.buffer);
+        self.ctx.clear();
     }
 }
 
diff --git a/lang/src/backend/hbvm.rs b/lang/src/backend/hbvm.rs
index 52ffe59..805d0af 100644
--- a/lang/src/backend/hbvm.rs
+++ b/lang/src/backend/hbvm.rs
@@ -229,8 +229,8 @@ impl Backend for HbvmBackend {
         let functions = types
             .ins
             .funcs
-            .iter()
-            .zip(self.funcs.iter())
+            .values()
+            .zip(self.funcs.values())
             .filter(|(_, f)| f.offset != u32::MAX)
             .map(|(f, fd)| {
                 let name = if f.file != Module::default() {
@@ -245,8 +245,8 @@ impl Backend for HbvmBackend {
                 types
                     .ins
                     .globals
-                    .iter()
-                    .zip(self.globals.iter())
+                    .values()
+                    .zip(self.globals.values())
                     .filter(|(_, g)| g.offset != u32::MAX)
                     .map(|(g, gd)| {
                         let name = if g.file == Module::default() {
diff --git a/lang/src/son.rs b/lang/src/son.rs
index ec8fab4..bdff748 100644
--- a/lang/src/son.rs
+++ b/lang/src/son.rs
@@ -4258,24 +4258,43 @@ impl<'a> Codegen<'a> {
                             "the simbol name is limmited to 63 characters, please don't import java",
                         );
                     };
+
                     name
                 } else {
                     name
                 };
 
-                let func = FuncData {
-                    file: sc.file,
-                    parent: sc.parent,
-                    name,
-                    pos,
-                    sig,
-                    expr: ExprRef::new(expr),
-                    is_inline: sc.is_ct,
-                    is_generic: false,
-                    is_import: true,
-                    comp_state: [CompState::Compiled.into(); 2],
-                };
-                self.tys.ins.funcs.push(func).into()
+                if let Some(f) = self
+                    .tys
+                    .ins
+                    .funcs
+                    .values()
+                    .find(|f| f.name == name && f.is_import && f.pos != pos)
+                {
+                    self.error_low(sc.file, pos, "second import of this symbol");
+                    self.error_low(sc.file, f.pos, "...previous occured here");
+                }
+
+                *self.tys.syms.get_or_insert(
+                    SymKey::Import(sc.parent, name),
+                    &mut self.tys.ins,
+                    |ins| {
+                        ins.funcs
+                            .push(FuncData {
+                                file: sc.file,
+                                parent: sc.parent,
+                                name,
+                                pos,
+                                sig,
+                                expr: ExprRef::new(expr),
+                                is_inline: sc.is_ct,
+                                is_generic: false,
+                                is_import: true,
+                                comp_state: [CompState::Compiled.into(); 2],
+                            })
+                            .into()
+                    },
+                )
             }
             Expr::Closure { pos, args, ret, .. } if let Some(name) = sc.name => {
                 match self.try_parse_concrete_signature(pos, sc, args, ret) {
diff --git a/lang/src/ty.rs b/lang/src/ty.rs
index 1b99de7..22f1979 100644
--- a/lang/src/ty.rs
+++ b/lang/src/ty.rs
@@ -143,6 +143,8 @@ impl crate::ctx_map::CtxEntry for Id {
                 let fc = &ctx.funcs[f];
                 if fc.is_generic {
                     SymKey::Type(fc.parent, fc.pos, fc.sig.args)
+                } else if fc.is_import {
+                    SymKey::Import(fc.parent, fc.name)
                 } else {
                     SymKey::Decl(fc.parent, fc.name)
                 }
@@ -643,6 +645,8 @@ pub enum SymKey<'a> {
     Optional(&'a OptData),
     Type(Id, Pos, List),
     Decl(Id, Ident),
+    // separate to avoid colision with decl
+    Import(Id, Ident),
     Array(&'a ArrayData),
     Constant(&'a ConstData),
 }
diff --git a/lang/src/utils.rs b/lang/src/utils.rs
index 0a9bdb4..6c45399 100644
--- a/lang/src/utils.rs
+++ b/lang/src/utils.rs
@@ -646,7 +646,7 @@ impl<K: Ent, T> EntVec<K, T> {
         }
     }
 
-    pub fn iter(&self) -> core::slice::Iter<T> {
+    pub fn values(&self) -> core::slice::Iter<T> {
         self.data.iter()
     }
 }