diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index cdf921c3c6..c2d6875e0c 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -2518,6 +2518,10 @@ bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
     // A percent is probably part of a formatting specification, such as %lld.
     if (Left.is(tok::percent))
       return false;
+    // Preserve the existence of a space before a percent for cases like 0x%04x
+    // and "%d %d"
+    if (Left.is(tok::numeric_constant) && Right.is(tok::percent))
+      return Right.WhitespaceRange.getEnd() != Right.WhitespaceRange.getBegin();
   } else if (Style.Language == FormatStyle::LK_JavaScript) {
     if (Left.is(TT_JsFatArrow))
       return true;
diff --git a/unittests/Format/FormatTestProto.cpp b/unittests/Format/FormatTestProto.cpp
index 672fd5914d..4b1480b074 100644
--- a/unittests/Format/FormatTestProto.cpp
+++ b/unittests/Format/FormatTestProto.cpp
@@ -442,9 +442,11 @@ TEST_F(FormatTestProto, FormatsOptionsExtensions) {
                "};");
 }
 
-TEST_F(FormatTestProto, NoSpaceAfterPercent) {
+TEST_F(FormatTestProto, SpacesAroundPercents) {
   verifyFormat("option (MyProto.options) = {\n"
                "  key: %lld\n"
+               "  key: 0x%04x\n"
+               "  key: \"%d %d\"\n"
                "};");
 }
 
diff --git a/unittests/Format/FormatTestTextProto.cpp b/unittests/Format/FormatTestTextProto.cpp
index 2cd7fb7bdf..4e4387b9d3 100644
--- a/unittests/Format/FormatTestTextProto.cpp
+++ b/unittests/Format/FormatTestTextProto.cpp
@@ -419,8 +419,10 @@ TEST_F(FormatTestTextProto, FormatsExtensions) {
       "}");
 }
 
-TEST_F(FormatTestTextProto, NoSpaceAfterPercent) {
+TEST_F(FormatTestTextProto, SpacesAroundPercents) {
   verifyFormat("key: %d");
+  verifyFormat("key: 0x%04x");
+  verifyFormat("key: \"%d %d\"");
 }
 
 TEST_F(FormatTestTextProto, FormatsRepeatedListInitializers) {