diff --git a/src/cli/Build.go b/src/cli/Build.go
index 28510cd..bfb7e37 100644
--- a/src/cli/Build.go
+++ b/src/cli/Build.go
@@ -8,7 +8,6 @@ import (
 
 	"git.akyoto.dev/cli/q/src/build"
 	"git.akyoto.dev/cli/q/src/config"
-	"git.akyoto.dev/cli/q/src/errors"
 )
 
 // Build parses the arguments and creates a build.
@@ -46,7 +45,7 @@ func buildExecutable(args []string) (*build.Build, error) {
 			i++
 
 			if i >= len(args) {
-				return b, &errors.ExpectedCLIParameter{Parameter: "arch"}
+				return b, &ExpectedParameterError{Parameter: "arch"}
 			}
 
 			config.TargetArch = args[i]
@@ -55,7 +54,7 @@ func buildExecutable(args []string) (*build.Build, error) {
 			i++
 
 			if i >= len(args) {
-				return b, &errors.ExpectedCLIParameter{Parameter: "os"}
+				return b, &ExpectedParameterError{Parameter: "os"}
 			}
 
 			switch args[i] {
@@ -66,12 +65,12 @@ func buildExecutable(args []string) (*build.Build, error) {
 			case "windows":
 				config.TargetOS = config.Windows
 			default:
-				return b, &errors.InvalidParameterValue{Value: args[i], Parameter: "os"}
+				return b, &InvalidValueError{Value: args[i], Parameter: "os"}
 			}
 
 		default:
 			if strings.HasPrefix(args[i], "-") {
-				return b, &errors.UnknownCLIParameter{Parameter: args[i]}
+				return b, &UnknownParameterError{Parameter: args[i]}
 			}
 
 			b.Files = append(b.Files, args[i])
@@ -79,7 +78,7 @@ func buildExecutable(args []string) (*build.Build, error) {
 	}
 
 	if config.TargetOS == config.Unknown {
-		return b, &errors.InvalidParameterValue{Value: runtime.GOOS, Parameter: "os"}
+		return b, &InvalidValueError{Value: runtime.GOOS, Parameter: "os"}
 	}
 
 	if len(b.Files) == 0 {
diff --git a/src/cli/errors.go b/src/cli/errors.go
new file mode 100644
index 0000000..5f675d6
--- /dev/null
+++ b/src/cli/errors.go
@@ -0,0 +1,34 @@
+package cli
+
+import "fmt"
+
+// ExpectedParameterError is created when a command line parameter is missing.
+type ExpectedParameterError struct {
+	Parameter string
+}
+
+// UnknownParameterError is created when a command line parameter is not recognized.
+type UnknownParameterError struct {
+	Parameter string
+}
+
+// InvalidValueError is created when a parameter has an invalid value.
+type InvalidValueError struct {
+	Value     string
+	Parameter string
+}
+
+// Error generates the string representation.
+func (err *ExpectedParameterError) Error() string {
+	return fmt.Sprintf("Expected parameter '%s'", err.Parameter)
+}
+
+// Error generates the string representation.
+func (err *UnknownParameterError) Error() string {
+	return fmt.Sprintf("Unknown parameter '%s'", err.Parameter)
+}
+
+// Error generates the string representation.
+func (err *InvalidValueError) Error() string {
+	return fmt.Sprintf("Invalid value '%s' for parameter '%s'", err.Value, err.Parameter)
+}
diff --git a/src/cli/exit.go b/src/cli/exit.go
index 69f8460..aefa74e 100644
--- a/src/cli/exit.go
+++ b/src/cli/exit.go
@@ -3,23 +3,22 @@ package cli
 import (
 	"errors"
 	"os/exec"
-
-	xerrors "git.akyoto.dev/cli/q/src/errors"
 )
 
 // exit returns the exit code depending on the error type.
 func exit(err error) int {
 	var (
 		exit              *exec.ExitError
-		expectedParameter *xerrors.ExpectedCLIParameter
-		unknownParameter  *xerrors.UnknownCLIParameter
+		expectedParameter *ExpectedParameterError
+		unknownParameter  *UnknownParameterError
+		invalidValue      *InvalidValueError
 	)
 
 	if errors.As(err, &exit) {
 		return exit.ExitCode()
 	}
 
-	if errors.As(err, &expectedParameter) || errors.As(err, &unknownParameter) {
+	if errors.As(err, &expectedParameter) || errors.As(err, &unknownParameter) || errors.As(err, &invalidValue) {
 		return 2
 	}
 
diff --git a/src/errors/ExpectedCLIParameter.go b/src/errors/ExpectedCLIParameter.go
deleted file mode 100644
index 0c25c6b..0000000
--- a/src/errors/ExpectedCLIParameter.go
+++ /dev/null
@@ -1,13 +0,0 @@
-package errors
-
-import "fmt"
-
-// ExpectedCLIParameter error is created when a command line parameter is missing.
-type ExpectedCLIParameter struct {
-	Parameter string
-}
-
-// Error generates the string representation.
-func (err *ExpectedCLIParameter) Error() string {
-	return fmt.Sprintf("Expected parameter '%s'", err.Parameter)
-}
diff --git a/src/errors/InvalidParameterValue.go b/src/errors/InvalidParameterValue.go
deleted file mode 100644
index cd2989e..0000000
--- a/src/errors/InvalidParameterValue.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package errors
-
-import "fmt"
-
-// InvalidParameterValue error is created when a parameter has an invalid value.
-type InvalidParameterValue struct {
-	Value     string
-	Parameter string
-}
-
-// Error generates the string representation.
-func (err *InvalidParameterValue) Error() string {
-	return fmt.Sprintf("Invalid value '%s' for parameter '%s'", err.Value, err.Parameter)
-}
diff --git a/src/errors/UnknownCLIParameter.go b/src/errors/UnknownCLIParameter.go
deleted file mode 100644
index 136864e..0000000
--- a/src/errors/UnknownCLIParameter.go
+++ /dev/null
@@ -1,13 +0,0 @@
-package errors
-
-import "fmt"
-
-// UnknownCLIParameter error is created when a command line parameter is not recognized.
-type UnknownCLIParameter struct {
-	Parameter string
-}
-
-// Error generates the string representation.
-func (err *UnknownCLIParameter) Error() string {
-	return fmt.Sprintf("Unknown parameter '%s'", err.Parameter)
-}