diff --git a/src/TransformOperationExecutor.ts b/src/TransformOperationExecutor.ts
index 0533f03df..186f9778d 100644
--- a/src/TransformOperationExecutor.ts
+++ b/src/TransformOperationExecutor.ts
@@ -104,6 +104,7 @@ export class TransformOperationExecutor {
       return String(value);
     } else if (targetType === Number && !isMap) {
       if (value === null || value === undefined) return value;
+      if (value === '') return null;
       return Number(value);
     } else if (targetType === Boolean && !isMap) {
       if (value === null || value === undefined) return value;
diff --git a/test/functional/implicit-type-declarations.spec.ts b/test/functional/implicit-type-declarations.spec.ts
index 889565512..aab5abb9e 100644
--- a/test/functional/implicit-type-declarations.spec.ts
+++ b/test/functional/implicit-type-declarations.spec.ts
@@ -13,6 +13,9 @@ describe('implicit type conversion', () => {
 
       @Expose()
       readonly implicitTypeString: string;
+
+      @Expose()
+      readonly implicitTypeEmptyNumber: number;
     }
 
     const result1: SimpleExample = plainToInstance(
@@ -20,6 +23,7 @@ describe('implicit type conversion', () => {
       {
         implicitTypeNumber: '100',
         implicitTypeString: 133123,
+        implicitTypeEmptyNumber: '',
       },
       { enableImplicitConversion: true }
     );
@@ -29,12 +33,13 @@ describe('implicit type conversion', () => {
       {
         implicitTypeNumber: '100',
         implicitTypeString: 133123,
+        implicitTypeEmptyNumber: '',
       },
       { enableImplicitConversion: false }
     );
 
-    expect(result1).toEqual({ implicitTypeNumber: 100, implicitTypeString: '133123' });
-    expect(result2).toEqual({ implicitTypeNumber: '100', implicitTypeString: 133123 });
+    expect(result1).toEqual({ implicitTypeNumber: 100, implicitTypeString: '133123', implicitTypeEmptyNumber: null });
+    expect(result2).toEqual({ implicitTypeNumber: '100', implicitTypeString: 133123, implicitTypeEmptyNumber: '' });
   });
 });