Index: ELF/Symbols.cpp
===================================================================
--- ELF/Symbols.cpp
+++ ELF/Symbols.cpp
@@ -212,6 +212,8 @@
                              uint8_t StOther, uint8_t Type, InputFile *File)
     : Defined(SymbolBody::DefinedCommonKind, N, StOther, Type),
       Alignment(Alignment), Size(Size) {
+  if (Alignment == 0)
+    fatal(getFilename(File) + ": common symbol '" + N + "' alignment is 0");
   this->File = File;
 }
 
Index: test/ELF/invalid/common-symbol-alignment.s
===================================================================
--- test/ELF/invalid/common-symbol-alignment.s
+++ test/ELF/invalid/common-symbol-alignment.s
@@ -0,0 +1,6 @@
+# REQUIRES: x86
+
+## common-symbol-alignment.elf contains common symbol with zero alignment.
+# RUN: not ld.lld %S/Inputs/common-symbol-alignment.elf \
+# RUN:   -o %t 2>&1 | FileCheck %s
+# CHECK: common symbol 'bar' alignment is 0