Index: lib/Format/WhitespaceManager.cpp
===================================================================
--- lib/Format/WhitespaceManager.cpp
+++ lib/Format/WhitespaceManager.cpp
@@ -675,7 +675,7 @@
     unsigned FirstTabWidth =
         Style.TabWidth - WhitespaceStartColumn % Style.TabWidth;
     // Indent with tabs only when there's at least one full tab.
-    if (FirstTabWidth + Style.TabWidth <= Spaces) {
+    if (Style.TabWidth <= Spaces) {
       Spaces -= FirstTabWidth;
       Text.append("\t");
     }
Index: unittests/Format/FormatTest.cpp
===================================================================
--- unittests/Format/FormatTest.cpp
+++ unittests/Format/FormatTest.cpp
@@ -9367,6 +9367,18 @@
                    "int oneTwoThree = 123;\n"
                    "int oneTwo = 12;",
                    Alignment));
+  // Test with use of tabs for alignment
+  FormatStyle::UseTabStyle OldTabStyle = Alignment.UseTab;
+  unsigned OldTabWidth = Alignment.TabWidth;
+  Alignment.UseTab = FormatStyle::UT_Always;
+  Alignment.TabWidth = 4;
+  verifyFormat("int a\t = 42;\n"
+               "int aa   = 42;\n"
+               "int aaa  = 42;\n"
+               "int aaaa = 42;",
+               Alignment);
+  Alignment.UseTab = OldTabStyle;
+  Alignment.TabWidth = OldTabWidth;
   Alignment.AlignEscapedNewlines = FormatStyle::ENAS_DontAlign;
   verifyFormat("#define A \\\n"
                "  int aaaa       = 12; \\\n"
@@ -9542,6 +9554,18 @@
                    "unsigned oneTwoThree = 123;\n"
                    "int oneTwo = 12;",
                    Alignment));
+  // Test with use of tabs for alignment
+  FormatStyle::UseTabStyle OldTabStyle = Alignment.UseTab;
+  unsigned OldTabWidth = Alignment.TabWidth;
+  Alignment.UseTab = FormatStyle::UT_Always;
+  Alignment.TabWidth = 4;
+  verifyFormat("int\t   a = 42;\n"
+               "float  b = 42;\n"
+               "char   c = 42;\n"
+               "double d = 42;",
+               Alignment);
+  Alignment.UseTab = OldTabStyle;
+  Alignment.TabWidth = OldTabWidth;
   // Function prototype alignment
   verifyFormat("int    a();\n"
                "double b();",