diff --git a/lib/src/rules/unnecessary_null_checks.dart b/lib/src/rules/unnecessary_null_checks.dart
index aa56c72..577bd29 100644
--- a/lib/src/rules/unnecessary_null_checks.dart
+++ b/lib/src/rules/unnecessary_null_checks.dart
@@ -68,12 +68,6 @@
       rule.reportLintForToken(node.operator);
     }
   }
-
-  void reportIfNullable(PostfixExpression node, DartType type) {
-    if (type != null && context.typeSystem.isNullable(type)) {
-      rule.reportLintForToken(node.operator);
-    }
-  }
 }
 
 DartType getExpectedType(PostfixExpression node) {
@@ -88,7 +82,12 @@
         .returnType;
   }
   // assignment
-  if (parent is AssignmentExpression) {
+  if (parent is AssignmentExpression &&
+      parent.operator.type == TokenType.EQ &&
+      (parent.leftHandSide is! Identifier ||
+          node.operand is! Identifier ||
+          (parent.leftHandSide as Identifier).name !=
+              (node.operand as Identifier).name)) {
     return parent.writeType;
   }
   // in variable declaration
diff --git a/test/rules/experiments/nnbd/rules/unnecessary_null_checks.dart b/test/rules/experiments/nnbd/rules/unnecessary_null_checks.dart
index 7a80657..cc7703c 100644
--- a/test/rules/experiments/nnbd/rules/unnecessary_null_checks.dart
+++ b/test/rules/experiments/nnbd/rules/unnecessary_null_checks.dart
@@ -38,3 +38,19 @@
   int? v;
   v = i!; // LINT
 }
+
+f4(int? p) {
+  int? v;
+  v ??= 1;
+  v += p!; // OK
+}
+
+autoPromote() {
+  int? v2;
+  v2 = v2!; // OK
+}
+
+f5(int? p) {
+  int? v1;
+  v1 ??= p!; // OK
+}