Index: test/wasm/import-module.ll
===================================================================
--- test/wasm/import-module.ll
+++ test/wasm/import-module.ll
@@ -0,0 +1,21 @@
+; RUN: llc -filetype=obj %s -o %t.o
+; RUN: wasm-ld --allow-undefined -o %t.wasm %t.o
+; RUN: obj2yaml %t.wasm | FileCheck %s
+
+target triple = "wasm32-unknown-unknown-wasm"
+
+define void @_start() {
+  call void @foo();
+  ret void
+}
+
+declare void @foo() #0
+
+attributes #0 = { "wasm-import-module"="bar" }
+
+; CHECK:        - Type:            IMPORT
+; CHECK-NEXT:     Imports:         
+; CHECK-NEXT:       - Module:          bar
+; CHECK-NEXT:         Field:           foo
+; CHECK-NEXT:         Kind:            FUNCTION
+; CHECK-NEXT:         SigIndex:        0
Index: wasm/InputFiles.cpp
===================================================================
--- wasm/InputFiles.cpp
+++ wasm/InputFiles.cpp
@@ -378,7 +378,8 @@
 
   switch (Sym.Info.Kind) {
   case WASM_SYMBOL_TYPE_FUNCTION:
-    return Symtab->addUndefinedFunction(Name, Flags, this, Sym.Signature);
+    return Symtab->addUndefinedFunction(Name, Sym.Info.Module, Flags, this,
+                                        Sym.Signature);
   case WASM_SYMBOL_TYPE_DATA:
     return Symtab->addUndefinedData(Name, Flags, this);
   case WASM_SYMBOL_TYPE_GLOBAL:
@@ -446,7 +447,7 @@
 
   if (ObjSym.isUndefined()) {
     if (ObjSym.isExecutable())
-      return Symtab->addUndefinedFunction(Name, Flags, &F, nullptr);
+      return Symtab->addUndefinedFunction(Name, kDefaultModule, Flags, &F, nullptr);
     return Symtab->addUndefinedData(Name, Flags, &F);
   }
 
Index: wasm/LTO.h
===================================================================
--- wasm/LTO.h
+++ wasm/LTO.h
@@ -22,6 +22,7 @@
 
 #include "lld/Common/LLVM.h"
 #include "llvm/ADT/SmallString.h"
+#include "Writer.h"
 #include <memory>
 #include <vector>
 
Index: wasm/LTO.cpp
===================================================================
--- wasm/LTO.cpp
+++ wasm/LTO.cpp
@@ -80,8 +80,8 @@
 
 static void undefine(Symbol *S) {
   if (auto F = dyn_cast<DefinedFunction>(S))
-    replaceSymbol<UndefinedFunction>(F, F->getName(), 0, F->getFile(),
-                                     F->Signature);
+    replaceSymbol<UndefinedFunction>(F, F->getName(), kDefaultModule, 0,
+                                     F->getFile(), F->Signature);
   else if (isa<DefinedData>(S))
     replaceSymbol<UndefinedData>(S, S->getName(), 0, S->getFile());
   else
Index: wasm/SymbolTable.h
===================================================================
--- wasm/SymbolTable.h
+++ wasm/SymbolTable.h
@@ -58,8 +58,8 @@
   Symbol *addDefinedEvent(StringRef Name, uint32_t Flags, InputFile *File,
                           InputEvent *E);
 
-  Symbol *addUndefinedFunction(StringRef Name, uint32_t Flags, InputFile *File,
-                               const WasmSignature *Signature);
+  Symbol *addUndefinedFunction(StringRef Name, StringRef Module, uint32_t Flags,
+                               InputFile *File, const WasmSignature *Signature);
   Symbol *addUndefinedData(StringRef Name, uint32_t Flags, InputFile *File);
   Symbol *addUndefinedGlobal(StringRef Name, uint32_t Flags, InputFile *File,
                              const WasmGlobalType *Type);
Index: wasm/SymbolTable.cpp
===================================================================
--- wasm/SymbolTable.cpp
+++ wasm/SymbolTable.cpp
@@ -315,8 +315,8 @@
   return S;
 }
 
-Symbol *SymbolTable::addUndefinedFunction(StringRef Name, uint32_t Flags,
-                                          InputFile *File,
+Symbol *SymbolTable::addUndefinedFunction(StringRef Name, StringRef Module,
+                                          uint32_t Flags, InputFile *File,
                                           const WasmSignature *Sig) {
   LLVM_DEBUG(dbgs() << "addUndefinedFunction: " << Name <<
              " [" << (Sig ? toString(*Sig) : "none") << "]\n");
@@ -326,7 +326,7 @@
   std::tie(S, WasInserted) = insert(Name, File);
 
   if (WasInserted)
-    replaceSymbol<UndefinedFunction>(S, Name, Flags, File, Sig);
+    replaceSymbol<UndefinedFunction>(S, Name, Module, Flags, File, Sig);
   else if (auto *Lazy = dyn_cast<LazySymbol>(S))
     Lazy->fetch();
   else
Index: wasm/Symbols.h
===================================================================
--- wasm/Symbols.h
+++ wasm/Symbols.h
@@ -155,13 +155,17 @@
 
 class UndefinedFunction : public FunctionSymbol {
 public:
-  UndefinedFunction(StringRef Name, uint32_t Flags, InputFile *File = nullptr,
+  UndefinedFunction(StringRef Name, StringRef Module, uint32_t Flags,
+                    InputFile *File = nullptr,
                     const WasmSignature *Type = nullptr)
-      : FunctionSymbol(Name, UndefinedFunctionKind, Flags, File, Type) {}
+      : FunctionSymbol(Name, UndefinedFunctionKind, Flags, File, Type),
+        Module(Module) {}
 
   static bool classof(const Symbol *S) {
     return S->kind() == UndefinedFunctionKind;
   }
+
+  StringRef Module;
 };
 
 class SectionSymbol : public Symbol {
Index: wasm/Writer.h
===================================================================
--- wasm/Writer.h
+++ wasm/Writer.h
@@ -14,6 +14,8 @@
 
 void writeResult();
 
+extern const char *kDefaultModule;
+
 } // namespace wasm
 } // namespace lld
 
Index: wasm/Writer.cpp
===================================================================
--- wasm/Writer.cpp
+++ wasm/Writer.cpp
@@ -41,6 +41,7 @@
 
 static constexpr int kStackAlignment = 16;
 static constexpr const char *kFunctionTableName = "__indirect_function_table";
+const char *lld::wasm::kDefaultModule = "env";
 
 namespace {
 
@@ -156,7 +157,7 @@
 
   if (Config->ImportMemory) {
     WasmImport Import;
-    Import.Module = "env";
+    Import.Module = kDefaultModule;
     Import.Field = "memory";
     Import.Kind = WASM_EXTERNAL_MEMORY;
     Import.Memory.Flags = 0;
@@ -173,7 +174,7 @@
   if (Config->ImportTable) {
     uint32_t TableSize = TableBase + IndirectFunctions.size();
     WasmImport Import;
-    Import.Module = "env";
+    Import.Module = kDefaultModule;
     Import.Field = kFunctionTableName;
     Import.Kind = WASM_EXTERNAL_TABLE;
     Import.Table.ElemType = WASM_TYPE_FUNCREF;
@@ -183,7 +184,11 @@
 
   for (const Symbol *Sym : ImportedSymbols) {
     WasmImport Import;
-    Import.Module = "env";
+    if (auto *F = dyn_cast<UndefinedFunction>(Sym))
+      Import.Module = F->Module;
+    else
+      Import.Module = kDefaultModule;
+
     Import.Field = Sym->getName();
     if (auto *FunctionSym = dyn_cast<FunctionSymbol>(Sym)) {
       Import.Kind = WASM_EXTERNAL_FUNCTION;