diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3191,11 +3191,6 @@
     if (Left.is(TT_CSharpNullCoalescing) || Right.is(TT_CSharpNullCoalescing))
       return true;
 
-    // Space before and after '??='.
-    if (Left.is(TT_CSharpNullCoalescingAssignment) ||
-        Right.is(TT_CSharpNullCoalescingAssignment))
-      return true;
-
     // No space before null forgiving '!'.
     if (Right.is(TT_JsNonNullAssertion))
       return false;
diff --git a/clang/unittests/Format/FormatTestCSharp.cpp b/clang/unittests/Format/FormatTestCSharp.cpp
--- a/clang/unittests/Format/FormatTestCSharp.cpp
+++ b/clang/unittests/Format/FormatTestCSharp.cpp
@@ -359,8 +359,16 @@
 }
 
 TEST_F(FormatTestCSharp, CSharpNullCoalescingAssignment) {
-  verifyFormat("test \?\?= ABC;");
-  verifyFormat("test \?\?= true;");
+  FormatStyle Style = getGoogleStyle(FormatStyle::LK_CSharp);
+  Style.SpaceBeforeAssignmentOperators = true;
+
+  verifyFormat("test \?\?= ABC;", Style);
+  verifyFormat("test \?\?= true;", Style);
+
+  Style.SpaceBeforeAssignmentOperators = false;
+
+  verifyFormat("test\?\?= ABC;", Style);
+  verifyFormat("test\?\?= true;", Style);
 }
 
 TEST_F(FormatTestCSharp, CSharpNullForgiving) {