diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmInfo.h b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmInfo.h
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmInfo.h
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmInfo.h
@@ -19,6 +19,7 @@
 class SystemZMCAsmInfo : public MCAsmInfoELF {
 public:
   explicit SystemZMCAsmInfo(const Triple &TT);
+  bool isAcceptableChar(char C) const override;
 };
 
 } // end namespace llvm
diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmInfo.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmInfo.cpp
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmInfo.cpp
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmInfo.cpp
@@ -37,3 +37,10 @@
   SupportsDebugInformation = true;
   ExceptionsType = ExceptionHandling::DwarfCFI;
 }
+
+bool SystemZMCAsmInfo::isAcceptableChar(char C) const {
+  if (AssemblerDialect == AD_ATT)
+    return MCAsmInfo::isAcceptableChar(C);
+
+  return MCAsmInfo::isAcceptableChar(C) || C == '#';
+}
diff --git a/llvm/unittests/MC/SystemZ/SystemZAsmLexerTest.cpp b/llvm/unittests/MC/SystemZ/SystemZAsmLexerTest.cpp
--- a/llvm/unittests/MC/SystemZ/SystemZAsmLexerTest.cpp
+++ b/llvm/unittests/MC/SystemZ/SystemZAsmLexerTest.cpp
@@ -48,6 +48,7 @@
     AllowHashAtStartOfIdentifier = Value;
   }
   void setAllowDotIsPC(bool Value) { DotIsPC = Value; }
+  void setAssemblerDialect(unsigned Value) { AssemblerDialect = Value; }
 };
 
 // Setup a testing class that the GTest framework can call.
@@ -734,4 +735,19 @@
        AsmToken::Error, AsmToken::EndOfStatement, AsmToken::Eof});
   lexAndCheckTokens(AsmStr, ExpectedTokens);
 }
+
+TEST_F(SystemZAsmLexerTest, CheckPrintAcceptableSymbol) {
+  std::string AsmStr = "ab13_$.@";
+  EXPECT_EQ(true, MUPMAI->isValidUnquotedName(AsmStr));
+  AsmStr += "#";
+  EXPECT_EQ(false, MUPMAI->isValidUnquotedName(AsmStr));
+}
+
+TEST_F(SystemZAsmLexerTest, CheckPrintAcceptableSymbol2) {
+  MUPMAI->setAssemblerDialect(1);
+  std::string AsmStr = "ab13_$.@";
+  EXPECT_EQ(true, MUPMAI->isValidUnquotedName(AsmStr));
+  AsmStr += "#";
+  EXPECT_EQ(true, MUPMAI->isValidUnquotedName(AsmStr));
+}
 } // end anonymous namespace