diff --git a/clang/lib/Format/WhitespaceManager.cpp b/clang/lib/Format/WhitespaceManager.cpp
--- a/clang/lib/Format/WhitespaceManager.cpp
+++ b/clang/lib/Format/WhitespaceManager.cpp
@@ -353,6 +353,10 @@
         if (Changes[i].Tok->is(TT_ConditionalExpr))
           return true;
 
+        // Period Initializer .XXX = 1.
+        if (Changes[i].Tok->is(TT_DesignatedInitializerPeriod))
+          return true;
+
         // Continued ternary operator
         if (Changes[i].Tok->Previous &&
             Changes[i].Tok->Previous->is(TT_ConditionalExpr))
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -16272,6 +16272,52 @@
   // clang-format on
 }
 
+TEST_F(FormatTest, AlignWithInitializerPeriods) {
+  auto Style = getLLVMStyleWithColumns(60);
+
+  verifyFormat("void foo1(void) {\n"
+               "  BYTE p[1] = 1;\n"
+               "  A B = {.one_foooooooooooooooo = 2,\n"
+               "         .two_fooooooooooooo = 3,\n"
+               "         .three_fooooooooooooo = 4};\n"
+               "  BYTE payload = 2;\n"
+               "}",
+               Style);
+
+  Style.AlignConsecutiveAssignments = FormatStyle::ACS_Consecutive;
+  Style.AlignConsecutiveDeclarations = FormatStyle::ACS_None;
+  verifyFormat("void foo2(void) {\n"
+               "  BYTE p[1]    = 1;\n"
+               "  A B          = {.one_foooooooooooooooo = 2,\n"
+               "                  .two_fooooooooooooo    = 3,\n"
+               "                  .three_fooooooooooooo  = 4};\n"
+               "  BYTE payload = 2;\n"
+               "}",
+               Style);
+
+  Style.AlignConsecutiveAssignments = FormatStyle::ACS_None;
+  Style.AlignConsecutiveDeclarations = FormatStyle::ACS_Consecutive;
+  verifyFormat("void foo3(void) {\n"
+               "  BYTE p[1] = 1;\n"
+               "  A    B = {.one_foooooooooooooooo = 2,\n"
+               "            .two_fooooooooooooo = 3,\n"
+               "            .three_fooooooooooooo = 4};\n"
+               "  BYTE payload = 2;\n"
+               "}",
+               Style);
+
+  Style.AlignConsecutiveAssignments = FormatStyle::ACS_Consecutive;
+  Style.AlignConsecutiveDeclarations = FormatStyle::ACS_Consecutive;
+  verifyFormat("void foo4(void) {\n"
+               "  BYTE p[1]    = 1;\n"
+               "  A    B       = {.one_foooooooooooooooo = 2,\n"
+               "                  .two_fooooooooooooo    = 3,\n"
+               "                  .three_fooooooooooooo  = 4};\n"
+               "  BYTE payload = 2;\n"
+               "}",
+               Style);
+}
+
 TEST_F(FormatTest, LinuxBraceBreaking) {
   FormatStyle LinuxBraceStyle = getLLVMStyle();
   LinuxBraceStyle.BreakBeforeBraces = FormatStyle::BS_Linux;