diff --git a/packages/utils/src/shorthand-time.ts b/packages/utils/src/shorthand-time.ts
index 94f5c54f..c5e8551d 100644
--- a/packages/utils/src/shorthand-time.ts
+++ b/packages/utils/src/shorthand-time.ts
@@ -28,8 +28,9 @@ export const shorthandToMilliseconds = (
 
 		// Check if the string is purely numeric
 		if (Number.isNaN(Number(shorthand))) {
-			// Use a case-insensitive regex that supports decimals and 'ms' unit
-			const match = /^([\d.]+)\s*(ms|s|m|h|hr|d)$/i.exec(shorthand);
+			// Use a case-insensitive regex that supports decimals and 'ms' unit.
+			// The number must be well-formed (at most one decimal point and at least one digit).
+			const match = /^(\d+\.?\d*|\.\d+)\s*(ms|s|m|h|hr|d)$/i.exec(shorthand);
 
 			if (!match) {
 				throw new Error(
diff --git a/packages/utils/test/shorthand-time.test.ts b/packages/utils/test/shorthand-time.test.ts
index c043096a..8b26beae 100644
--- a/packages/utils/test/shorthand-time.test.ts
+++ b/packages/utils/test/shorthand-time.test.ts
@@ -34,6 +34,17 @@ describe("time parser", () => {
 			"Unsupported time format: \"1z\". Use 'ms', 's', 'm', 'h', 'hr', or 'd'.",
 		);
 	});
+	test("send in string with malformed number and valid unit throws", () => {
+		for (const value of ["1.2.3s", "1..5s", "..s", ".s", ".m"]) {
+			expect(() => shorthandToMilliseconds(value)).toThrowError(
+				`Unsupported time format: "${value}"`,
+			);
+		}
+	});
+	test("send in string with decimal edge cases", () => {
+		expect(shorthandToMilliseconds(".5s")).toBe(500);
+		expect(shorthandToMilliseconds("5.s")).toBe(5000);
+	});
 	test("send in string with number", () => {
 		expect(shorthandToMilliseconds("1000")).toBe(1000);
 	});