diff --git a/front/src/utils/__tests__/cast-as-positive-integer-or-null.test.ts b/front/src/utils/__tests__/cast-as-positive-integer-or-null.test.ts
index 1c3e9d10b..b9a88647c 100644
--- a/front/src/utils/__tests__/cast-as-positive-integer-or-null.test.ts
+++ b/front/src/utils/__tests__/cast-as-positive-integer-or-null.test.ts
@@ -16,12 +16,12 @@ describe('canBeCastAsPositiveIntegerOrNull', () => {
     expect(canBeCastAsPositiveIntegerOrNull(-9)).toBeFalsy();
   });
 
-  it(`should return false if zero`, () => {
-    expect(canBeCastAsPositiveIntegerOrNull(0)).toBeFalsy();
+  it(`should return true if zero`, () => {
+    expect(canBeCastAsPositiveIntegerOrNull(0)).toBeTruthy();
   });
 
-  it(`should return false if string 0`, () => {
-    expect(canBeCastAsPositiveIntegerOrNull('0')).toBeFalsy();
+  it(`should return true if string 0`, () => {
+    expect(canBeCastAsPositiveIntegerOrNull('0')).toBeTruthy();
   });
 
   it(`should return false if negative float`, () => {
@@ -82,12 +82,12 @@ describe('castAsPositiveIntegerOrNull', () => {
     expect(castAsPositiveIntegerOrNull('9')).toBe(9);
   });
 
-  it(`should throw if trying to cast a 0 to positive integer`, () => {
-    expect(() => castAsPositiveIntegerOrNull(0)).toThrow(Error);
+  it(`should cast an integer to zero integer`, () => {
+    expect(castAsPositiveIntegerOrNull(0)).toBe(0);
   });
 
-  it(`should throw if trying to cast a string 0 to positive integer`, () => {
-    expect(() => castAsPositiveIntegerOrNull('0')).toThrow(Error);
+  it(`should cast an integer string to zero integer`, () => {
+    expect(castAsPositiveIntegerOrNull('0')).toBe(0);
   });
 
   it(`should throw if trying to cast a positive float string to positive integer`, () => {
diff --git a/front/src/utils/cast-as-positive-integer-or-null.ts b/front/src/utils/cast-as-positive-integer-or-null.ts
index 56ad707fe..1751fd4a3 100644
--- a/front/src/utils/cast-as-positive-integer-or-null.ts
+++ b/front/src/utils/cast-as-positive-integer-or-null.ts
@@ -8,7 +8,7 @@ export function canBeCastAsPositiveIntegerOrNull(
   if (typeof probablePositiveNumberOrNull === 'number') {
     return (
       Number.isInteger(probablePositiveNumberOrNull) &&
-      Math.sign(probablePositiveNumberOrNull) === 1
+      Math.sign(probablePositiveNumberOrNull) !== -1
     );
   }
 
@@ -27,7 +27,7 @@ export function canBeCastAsPositiveIntegerOrNull(
       return false;
     }
 
-    if (Number.isInteger(stringAsNumber) && Math.sign(stringAsNumber) === 1) {
+    if (Number.isInteger(stringAsNumber) && Math.sign(stringAsNumber) !== -1) {
       return true;
     }
   }