diff --git a/internal/interpreter/interpreter_error.go b/internal/interpreter/interpreter_error.go
index 1d5bc415..672b8558 100644
--- a/internal/interpreter/interpreter_error.go
+++ b/internal/interpreter/interpreter_error.go
@@ -27,6 +27,11 @@ func (e MissingFundsErr) Error() string {
 	return fmt.Sprintf("Not enough funds. Needed [%s %s] (only [%s %s] available)", e.Asset, e.Needed.String(), e.Asset, e.Available.String())
 }
 
+func (e MissingFundsErr) Is(target error) bool {
+	_, ok := target.(MissingFundsErr)
+	return ok
+}
+
 type InvalidMonetaryLiteral struct {
 	parser.Range
 	Source string
diff --git a/numscript.go b/numscript.go
index 98df032a..35bc10e0 100644
--- a/numscript.go
+++ b/numscript.go
@@ -72,6 +72,7 @@ type (
 	Value = interpreter.Value
 
 	InterpreterError = interpreter.InterpreterError
+	MissingFundsErr  = interpreter.MissingFundsErr
 )
 
 func (p ParseResult) Run(ctx context.Context, vars VariablesMap, store Store) (ExecutionResult, InterpreterError) {