diff --git a/plugins/src/calc/plugin.ron b/plugins/src/calc/plugin.ron
index 76bc3c5..8eba8af 100644
--- a/plugins/src/calc/plugin.ron
+++ b/plugins/src/calc/plugin.ron
@@ -2,7 +2,7 @@
     name: "Calculator with unit conversion (uses Qalculate! expressions)",
     description: "Syntax: = <expression>\nExample: = 10 J / (196x^2) = 4 kW/s",
     query: (
-        regex: "^[=\\-0-9].*",
+        regex: "^[=\\-0-9|(-0-9)].*",
         help: "= ",
         priority: High,
         isolate_with: "^(=).*",