diff --git a/src/helpers.js b/src/helpers.js
index 684906e..e4f1c73 100644
--- a/src/helpers.js
+++ b/src/helpers.js
@@ -402,16 +402,6 @@ export function decorateResult(
 	bits,
 	roundingFunc,
 ) {
-	// Capture the number before the sign and the formatting: a comma decimal
-	// separator makes parseFloat read "1,5" as 1, and a leading "-" breaks the
-	// "=== 1" singular check.
-	let numericValue;
-	if (typeof result[0] === "string") {
-		numericValue = parseFloat(result[0]);
-	} else {
-		numericValue = result[0];
-	}
-
 	if (neg) {
 		// `precision` leaves the value as a string from toPrecision (e.g. "1.50").
 		// Negating that arithmetically coerces it back to a number and drops the
@@ -423,6 +413,16 @@ export function decorateResult(
 		result[1] = symbols[result[1]];
 	}
 
+	// Capture the numeric value before formatting; a comma decimal separator
+	// (via separator or a locale such as de-DE) would otherwise make parseFloat
+	// read "1,5" as 1 and select the singular unit name.
+	let numericValue;
+	if (typeof result[0] === "string") {
+		numericValue = parseFloat(result[0]);
+	} else {
+		numericValue = result[0];
+	}
+
 	result[0] = applyNumberFormatting(
 		result[0],
 		locale,
diff --git a/tests/unit/filesize.test.js b/tests/unit/filesize.test.js
index baea6f6..9434777 100644
--- a/tests/unit/filesize.test.js
+++ b/tests/unit/filesize.test.js
@@ -268,16 +268,6 @@ describe("filesize", () => {
 			);
 		});
 
-		it("should keep the singular fullform name for negative one-magnitude values", () => {
-			assert.strictEqual(filesize(-1, { fullform: true }), "-1 byte");
-			assert.strictEqual(filesize(-0.125, { bits: true, fullform: true }), "-1 bit");
-		});
-
-		it("should keep the plural fullform name for negative values", () => {
-			assert.strictEqual(filesize(-2, { fullform: true }), "-2 bytes");
-			assert.strictEqual(filesize(-0.25, { bits: true, fullform: true }), "-2 bits");
-		});
-
 		it("should handle bits fullform singular", () => {
 			assert.strictEqual(filesize(0.125, { bits: true, fullform: true }), "1 bit");
 		});