diff --git a/llvm/lib/ToolDrivers/llvm-dlltool/Options.td b/llvm/lib/ToolDrivers/llvm-dlltool/Options.td
--- a/llvm/lib/ToolDrivers/llvm-dlltool/Options.td
+++ b/llvm/lib/ToolDrivers/llvm-dlltool/Options.td
@@ -24,3 +24,6 @@
 
 def f: JoinedOrSeparate<["-"], "f">, HelpText<"Assembler Flags">;
 def f_alias: JoinedOrSeparate<["--"], "as-flags">, Alias<f>;
+
+def t: JoinedOrSeparate<["-"], "t">, HelpText<"Prefix for temporary files (ignored)">;
+def t_alias: JoinedOrSeparate<["--"], "temp-prefix">, Alias<t>;
diff --git a/llvm/test/tools/llvm-dlltool/ignored-opts.def b/llvm/test/tools/llvm-dlltool/ignored-opts.def
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-dlltool/ignored-opts.def
@@ -0,0 +1,8 @@
+; RUN: llvm-dlltool -m i386 -d %s -l %t.a --temp-prefix foo
+; RUN: llvm-dlltool -m i386 -d %s -l %t.a --temp-prefix=foo
+; RUN: llvm-dlltool -m i386 -d %s -l %t.a -t foo
+; RUN: llvm-dlltool -m i386 -d %s -l %t.a -tfoo
+
+LIBRARY test.dll
+EXPORTS
+TestFunction