diff --git a/src/PowderCoating.Infrastructure/Services/CustomFormulaAiService.cs b/src/PowderCoating.Infrastructure/Services/CustomFormulaAiService.cs
index 0420d95..ce733e4 100644
--- a/src/PowderCoating.Infrastructure/Services/CustomFormulaAiService.cs
+++ b/src/PowderCoating.Infrastructure/Services/CustomFormulaAiService.cs
@@ -181,7 +181,7 @@ Rules:
             foreach (var kv in variables)
             {
                 expr.Parameters[kv.Key] = kv.Value.ValueKind == JsonValueKind.Number
-                    ? (object)kv.Value.GetDecimal()
+                    ? (object)kv.Value.GetDouble()
                     : (object)(kv.Value.GetString() ?? "");
             }