diff --git a/spec/actions_spec.lua b/spec/actions_spec.lua
index 593d7d1..c1a1f4c 100644
--- a/spec/actions_spec.lua
+++ b/spec/actions_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to actions", function()
    it("calls actions for options", function()
diff --git a/spec/arguments_spec.lua b/spec/arguments_spec.lua
index c2241fb..7857537 100644
--- a/spec/arguments_spec.lua
+++ b/spec/arguments_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to positional arguments", function()
    describe("passing correct arguments", function()
diff --git a/spec/commands_spec.lua b/spec/commands_spec.lua
index 7ae8851..5a0c7b0 100644
--- a/spec/commands_spec.lua
+++ b/spec/commands_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to commands", function()
    it("handles commands after arguments", function()
diff --git a/spec/convert_spec.lua b/spec/convert_spec.lua
index befd767..7d509f9 100644
--- a/spec/convert_spec.lua
+++ b/spec/convert_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to converters", function()
    it("converts arguments", function()
diff --git a/spec/default_spec.lua b/spec/default_spec.lua
index a80433e..55afe80 100644
--- a/spec/default_spec.lua
+++ b/spec/default_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to default values", function()
    describe("default values for arguments", function()
diff --git a/spec/help_spec.lua b/spec/help_spec.lua
index 726adbc..5753d1c 100644
--- a/spec/help_spec.lua
+++ b/spec/help_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to help message generation", function()
    it("creates correct help message for empty parser", function()
diff --git a/spec/integrity_spec.lua b/spec/integrity_spec.lua
index dcf4b78..c8233c1 100644
--- a/spec/integrity_spec.lua
+++ b/spec/integrity_spec.lua
@@ -1,5 +1,3 @@
-local Parser = require "argparse"
-
 describe("tests related to CLI behaviour #unsafe", function()
    describe("error messages", function()
       it("generates correct error message without arguments", function()
diff --git a/spec/mutex_spec.lua b/spec/mutex_spec.lua
index d3f92f5..8ee5640 100644
--- a/spec/mutex_spec.lua
+++ b/spec/mutex_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to mutexes", function()
    it("handles mutex correctly", function()
diff --git a/spec/options_spec.lua b/spec/options_spec.lua
index ab2d300..2cee54c 100644
--- a/spec/options_spec.lua
+++ b/spec/options_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to options", function()
    describe("passing correct options", function()
diff --git a/spec/pparse_spec.lua b/spec/pparse_spec.lua
index bfd2110..f4ad812 100644
--- a/spec/pparse_spec.lua
+++ b/spec/pparse_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to :pparse()", function()
    it("returns true and result on success", function()
diff --git a/spec/tip_spec.lua b/spec/tip_spec.lua
index d3d70b7..cebdec3 100644
--- a/spec/tip_spec.lua
+++ b/spec/tip_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to tips", function()
    describe("provides tips when data is too long", function()
diff --git a/spec/usage_spec.lua b/spec/usage_spec.lua
index 80cb2ce..c6846c5 100644
--- a/spec/usage_spec.lua
+++ b/spec/usage_spec.lua
@@ -1,4 +1,5 @@
 local Parser = require "argparse"
+getmetatable(Parser()).error = function(_, msg) error(msg) end
 
 describe("tests related to usage message generation", function()
    it("creates correct usage message for empty parser", function()
diff --git a/src/argparse.lua b/src/argparse.lua
index 86fa918..3d21955 100644
--- a/src/argparse.lua
+++ b/src/argparse.lua
@@ -941,12 +941,8 @@ function Parser:_parse(args, errhandler)
 end
 
 function Parser:error(msg)
-   if _TEST then
-      error(msg)
-   else
-      io.stderr:write(("%s\r\n\r\nError: %s\r\n"):format(self:get_usage(), msg))
-      os.exit(1)
-   end
+   io.stderr:write(("%s\r\n\r\nError: %s\r\n"):format(self:get_usage(), msg))
+   os.exit(1)
 end
 
 function Parser:parse(args)