diff --git a/spec/options_spec.lua b/spec/options_spec.lua
index 2cee54c..eaeeaab 100644
--- a/spec/options_spec.lua
+++ b/spec/options_spec.lua
@@ -17,6 +17,13 @@ describe("tests related to options", function()
          assert.same({server = "foo"}, args)
       end)
 
+      it("normalizes default target", function()
+         local parser = Parser()
+         parser:option("--from-server")
+         local args = parser:parse({"--from-server", "foo"})
+         assert.same({from_server = "foo"}, args)
+      end)
+
       it("handles non-standard charset", function()
          local parser = Parser()
          parser:option "/s"
diff --git a/src/argparse.lua b/src/argparse.lua
index 0f72156..0c531bd 100644
--- a/src/argparse.lua
+++ b/src/argparse.lua
@@ -783,7 +783,7 @@ function Parser:_parse(args, errhandler)
          end
 
          local type_ = option:_get_type()
-         targets[option] = option:_get_target()
+         targets[option] = option:_get_target():gsub("-", "_")
 
          if type_ == "counter" then
             result[targets[option]] = 0