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
@@ -2893,6 +2893,10 @@
     if (Left.is(TT_TemplateCloser) && Right.is(TT_StartOfName))
       return true;
 
+    // space after comma in '[,]'.
+    if (Left.is(tok::comma) && Right.is(tok::r_square))
+      return Style.SpacesInSquareBrackets;
+
     // space between keywords and paren e.g. "using ("
     if (Right.is(tok::l_paren))
       if (Left.isOneOf(tok::kw_using, Keywords.kw_async, Keywords.kw_when))
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
@@ -595,6 +595,10 @@
   verifyFormat(R"(bool[] xs = { true, true };)", Style);
   verifyFormat(R"(taskContext.Factory.Run(async () => doThing(args);)", Style);
   verifyFormat(R"(catch (TestException) when (innerFinallyExecuted))", Style);
+  verifyFormat(R"(private float[,] Values;)", Style);
+
+  Style.SpacesInSquareBrackets = true;
+  verifyFormat(R"(private float[, ] Values;)", Style);
 }
 
 } // namespace format