diff --git a/lld/COFF/Config.h b/lld/COFF/Config.h
index 823385228c53..801478149697 100644
--- a/lld/COFF/Config.h
+++ b/lld/COFF/Config.h
@@ -46,6 +46,7 @@ struct Configuration {
   std::string OutputFile;
   bool DoGC = true;
   bool Relocatable = true;
+  bool Force = false;
 
   // Symbols in this set are considered as live by the garbage collector.
   std::set<StringRef> GCRoots;
diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index 634b63c425b8..d2dbd96a8fe2 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -265,6 +265,10 @@ bool LinkerDriver::link(llvm::ArrayRef<const char *> ArgsArr) {
   if (Args.hasArg(OPT_verbose))
     Config->Verbose = true;
 
+  // Handle /force or /force:unresolved
+  if (Args.hasArg(OPT_force) || Args.hasArg(OPT_force_unresolved))
+    Config->Force = true;
+
   // Handle /entry
   if (auto *Arg = Args.getLastArg(OPT_entry)) {
     Config->EntryName = Arg->getValue();
diff --git a/lld/COFF/SymbolTable.cpp b/lld/COFF/SymbolTable.cpp
index 75157805d074..aae6b22b4a09 100644
--- a/lld/COFF/SymbolTable.cpp
+++ b/lld/COFF/SymbolTable.cpp
@@ -92,6 +92,12 @@ bool SymbolTable::reportRemainingUndefines() {
       }
     }
     llvm::errs() << "undefined symbol: " << Name << "\n";
+    // Remaining undefined symbols are not fatal if /force is specified.
+    // They are replaced with dummy defined symbols.
+    if (Config->Force) {
+      Sym->Body = new (Alloc) DefinedAbsolute(Name, 0);
+      continue;
+    }
     Ret = true;
   }
   return Ret;
diff --git a/lld/test/COFF/force.test b/lld/test/COFF/force.test
new file mode 100644
index 000000000000..69455a9b2dc9
--- /dev/null
+++ b/lld/test/COFF/force.test
@@ -0,0 +1,43 @@
+# RUN: yaml2obj < %s > %t.obj
+# RUN: not lld -flavor link2 /out:%t.exe %t.obj
+# RUN: FileCheck %s < %t.log
+# RUN: lld -flavor link2 /out:%t.exe %t.obj /force >& %t.log
+# RUN: FileCheck %s < %t.log
+
+# CHECK: undefined symbol: foo
+
+---
+header:
+  Machine:         IMAGE_FILE_MACHINE_AMD64
+  Characteristics: []
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       4
+    SectionData:     000000000000
+symbols:
+  - Name:            .text
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          6
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            mainCRTStartup
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            foo
+    Value:           0
+    SectionNumber:   0
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+...