diff --git a/e2e/calculator.po.ts b/e2e/calculator.po.ts
index ffe8a5f4eecd615aa1ea8460873a7955fdbc2909..6053029af65d2e09faa8a505e417fdbdadace995 100644
--- a/e2e/calculator.po.ts
+++ b/e2e/calculator.po.ts
@@ -286,13 +286,17 @@ export class CalculatorPage {
             if (await i.isDisplayed()) {
                 // N in YAXN child of SPP module must not be float
                 const isN = (await i.getAttribute("id")).includes("_N"); // @TODO strengthen this clodo test
+                // Ob in Grille is set to 0.5 but cannot exceed 0.58; do not touch it
+                const isOb = (await i.getAttribute("id")) === "Ob";
                 const hasDot = (await i.getAttribute("value")).includes(".");
                 const hasExponent = (await i.getAttribute("value")).includes("e");
                 let keys = "" + Math.floor(Math.random() * 9) + 1;
                 if (!hasDot && !hasExponent && !isN) {
                     keys = "." + keys;
                 }
-                await i.sendKeys(keys);
+                if (! isOb) {
+                    await i.sendKeys(keys);
+                }
             }
         });
     }