diff --git a/llvm/lib/Support/SpecialCaseList.cpp b/llvm/lib/Support/SpecialCaseList.cpp
index 5145cccc91e3b..2d84f7f22cd7b 100644
--- a/llvm/lib/Support/SpecialCaseList.cpp
+++ b/llvm/lib/Support/SpecialCaseList.cpp
@@ -137,18 +137,24 @@ bool SpecialCaseList::createInternal(const MemoryBuffer *MB,
 Expected<SpecialCaseList::Section *>
 SpecialCaseList::addSection(StringRef SectionStr, unsigned LineNo,
                             bool UseGlobs) {
-  Sections.emplace_back();
-  auto &Section = Sections.back();
-  Section.SectionStr = SectionStr;
-
-  if (auto Err = Section.SectionMatcher->insert(SectionStr, LineNo, UseGlobs)) {
+  auto it =
+      std::find_if(Sections.begin(), Sections.end(), [&](const Section &s) {
+        return s.SectionStr == SectionStr;
+      });
+  if (it == Sections.end()) {
+    Sections.emplace_back();
+    auto &sec = Sections.back();
+    sec.SectionStr = SectionStr;
+    it = std::prev(Sections.end());
+  }
+  if (auto Err = it->SectionMatcher->insert(SectionStr, LineNo, UseGlobs)) {
     return createStringError(errc::invalid_argument,
                              "malformed section at line " + Twine(LineNo) +
                                  ": '" + SectionStr +
                                  "': " + toString(std::move(Err)));
   }
 
-  return &Section;
+  return &(*it);
 }
 
 bool SpecialCaseList::parse(const MemoryBuffer *MB, std::string &Error) {
diff --git a/llvm/unittests/Support/SpecialCaseListTest.cpp b/llvm/unittests/Support/SpecialCaseListTest.cpp
index d6d5621116d72..16da11e2d7835 100644
--- a/llvm/unittests/Support/SpecialCaseListTest.cpp
+++ b/llvm/unittests/Support/SpecialCaseListTest.cpp
@@ -216,8 +216,9 @@ TEST_F(SpecialCaseListTest, NoTrigramsInARule) {
 }
 
 TEST_F(SpecialCaseListTest, RepetitiveRule) {
-  std::unique_ptr<SpecialCaseList> SCL = makeSpecialCaseList("fun:*bar*bar*bar*bar*\n"
-                                                             "fun:bar*\n");
+  std::unique_ptr<SpecialCaseList> SCL =
+      makeSpecialCaseList("fun:*bar*bar*bar*bar*\n"
+                          "fun:bar*\n");
   EXPECT_TRUE(SCL->inSection("", "fun", "bara"));
   EXPECT_FALSE(SCL->inSection("", "fun", "abara"));
   EXPECT_TRUE(SCL->inSection("", "fun", "barbarbarbar"));
@@ -226,7 +227,8 @@ TEST_F(SpecialCaseListTest, RepetitiveRule) {
 }
 
 TEST_F(SpecialCaseListTest, SpecialSymbolRule) {
-  std::unique_ptr<SpecialCaseList> SCL = makeSpecialCaseList("src:*c\\+\\+abi*\n");
+  std::unique_ptr<SpecialCaseList> SCL =
+      makeSpecialCaseList("src:*c\\+\\+abi*\n");
   EXPECT_TRUE(SCL->inSection("", "src", "c++abi"));
   EXPECT_FALSE(SCL->inSection("", "src", "c\\+\\+abi"));
 }
@@ -242,8 +244,9 @@ TEST_F(SpecialCaseListTest, PopularTrigram) {
 }
 
 TEST_F(SpecialCaseListTest, EscapedSymbols) {
-  std::unique_ptr<SpecialCaseList> SCL = makeSpecialCaseList("src:*c\\+\\+abi*\n"
-                                                             "src:*hello\\\\world*\n");
+  std::unique_ptr<SpecialCaseList> SCL =
+      makeSpecialCaseList("src:*c\\+\\+abi*\n"
+                          "src:*hello\\\\world*\n");
   EXPECT_TRUE(SCL->inSection("", "src", "dir/c++abi"));
   EXPECT_FALSE(SCL->inSection("", "src", "dir/c\\+\\+abi"));
   EXPECT_FALSE(SCL->inSection("", "src", "c\\+\\+abi"));
@@ -315,7 +318,9 @@ TEST_F(SpecialCaseListTest, Version3) {
                                                              "src:def\n"
                                                              "[sect2]\n"
                                                              "src:def\n"
-                                                             "src:def\n");
+                                                             "src:def\n"
+                                                             "[sect1]\n"
+                                                             "src:foo*\n");
   EXPECT_TRUE(SCL->inSection("sect1", "src", "fooz"));
   EXPECT_TRUE(SCL->inSection("sect1", "src", "barz"));
   EXPECT_FALSE(SCL->inSection("sect2", "src", "fooz"));
@@ -323,9 +328,9 @@ TEST_F(SpecialCaseListTest, Version3) {
   EXPECT_TRUE(SCL->inSection("sect2", "src", "def"));
   EXPECT_TRUE(SCL->inSection("sect1", "src", "def"));
 
-  EXPECT_EQ(2u, SCL->inSectionBlame("sect1", "src", "fooz"));
   EXPECT_EQ(4u, SCL->inSectionBlame("sect1", "src", "barz"));
   EXPECT_EQ(5u, SCL->inSectionBlame("sect1", "src", "def"));
   EXPECT_EQ(8u, SCL->inSectionBlame("sect2", "src", "def"));
+  EXPECT_EQ(10u, SCL->inSectionBlame("sect1", "src", "fooz"));
 }
-}
+} // namespace