Index: clang/lib/Analysis/UnsafeBufferUsage.cpp
===================================================================
--- clang/lib/Analysis/UnsafeBufferUsage.cpp
+++ clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -124,12 +124,18 @@
 // Returns a matcher that matches any expression 'e' such that `innerMatcher`
 // matches 'e' and 'e' is in an Unspecified Lvalue Context.
 static auto isInUnspecifiedLvalueContext(internal::Matcher<Expr> innerMatcher) {
-  auto isLvalueToRvalueCast = [](internal::Matcher<Expr> M) {
-    return implicitCastExpr(hasCastKind(CastKind::CK_LValueToRValue),
-                            castSubExpr(M));
-  };
-  //FIXME: add assignmentTo context...
-  return isLvalueToRvalueCast(innerMatcher);
+// clang-format off
+  return
+    expr(eachOf(
+      implicitCastExpr(
+        hasCastKind(CastKind::CK_LValueToRValue),
+        castSubExpr(innerMatcher)),
+      binaryOperator(
+        hasAnyOperatorName("="),
+        hasLHS(innerMatcher)
+      )
+    ));
+// clang-format off
 }
 } // namespace clang::ast_matchers
 
Index: clang/test/SemaCXX/warn-unsafe-buffer-usage-fixits-assign-to-array-subscr-on-ptr.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/warn-unsafe-buffer-usage-fixits-assign-to-array-subscr-on-ptr.cpp
@@ -0,0 +1,16 @@
+// RUN: cp %s %t.cpp
+// RUN: %clang_cc1 -std=c++20 -Wunsafe-buffer-usage -fixit %t.cpp
+// RUN: grep -v CHECK %t.cpp | FileCheck %s
+
+// TODO cases where we don't want fixits
+
+// The Fix-It for unsafe operation is trivially empty.
+// In order to test that our machinery recognizes that we can test if the variable declaration gets a Fix-It.
+// If the operation wasn't handled propertly the declaration won't get Fix-It.
+// By testing presence of the declaration Fix-It we indirectly test presence of the trivial Fix-It for its operations.
+void test() {
+  int *p = new int[10];
+  // CHECK: std::span<int> p {new int[10], 10};
+  p[5] = 1;
+  // CHECK: p[5] = 1;
+}