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
@@ -966,6 +966,10 @@
 
         unsigned NextColumn = SourceMgr.getSpellingColumnNumber(
             Changes[j].OriginalWhitespaceRange.getEnd());
+        // Handle files without newline before the end of file correct
+        if (Changes[j].Tok->is(tok::eof))
+          NextColumn = 1;
+
         // The start of the next token was previously aligned with the
         // start of this comment.
         WasAlignedWithStartOfNextLine =
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
@@ -17458,6 +17458,40 @@
                Alignment);
 }
 
+TEST_F(FormatTest, AlignTrailingComments) {
+  FormatStyle Style = getLLVMStyle();
+  EXPECT_EQ(Style.AlignTrailingComments, true);
+
+  verifyFormat("namespace test {\n"
+               "class C;\n"
+               "} // namespace test\n"
+               "// Lorem ipsum dolor sit amet, consectetur adipiscing elit. "
+               "Nullam cursus nunc\n"
+               "// non",
+               Style);
+  verifyFormat("namespace test {\n"
+               "class C;\n"
+               "} // namespace test\n"
+               "// Lorem ipsum dolor sit amet, consectetur adipiscing elit. "
+               "Nullam cursus nunc\n"
+               "// non\n",
+               Style);
+  verifyFormat("namespace test {\n"
+               "class C;\n"
+               "} // namespace test\n"
+               "// Lorem ipsum dolor sit amet, consectetur adipiscing elit. "
+               "Nullam cursus nunc\n"
+               "// non other text",
+               Style);
+  verifyFormat("namespace test {\n"
+               "class C;\n"
+               "} // namespace test\n"
+               "// Lorem ipsum dolor sit amet, consectetur adipiscing elit. "
+               "Nullam cursus nunc\n"
+               "// non other text\n",
+               Style);
+}
+
 TEST_F(FormatTest, AlignConsecutiveBitFields) {
   FormatStyle Alignment = getLLVMStyle();
   Alignment.AlignConsecutiveBitFields.Enabled = true;