diff --git a/lldb/include/lldb/Symbol/Block.h b/lldb/include/lldb/Symbol/Block.h
index 7c7a66de83199..d0063f132cc0f 100644
--- a/lldb/include/lldb/Symbol/Block.h
+++ b/lldb/include/lldb/Symbol/Block.h
@@ -40,7 +40,7 @@ namespace lldb_private {
 /// blocks.
 class Block : public UserID, public SymbolContextScope {
 public:
-  typedef RangeVector<uint32_t, uint32_t, 1> RangeList;
+  typedef RangeVector<int32_t, uint32_t, 1> RangeList;
   typedef RangeList::Entry Range;
 
   // Creates a block representing the whole function. Only meant to be used from
diff --git a/lldb/unittests/Utility/RangeMapTest.cpp b/lldb/unittests/Utility/RangeMapTest.cpp
index 0b4c236062f20..981fa2a7d1c34 100644
--- a/lldb/unittests/Utility/RangeMapTest.cpp
+++ b/lldb/unittests/Utility/RangeMapTest.cpp
@@ -12,6 +12,29 @@
 
 using namespace lldb_private;
 
+TEST(RangeVector, SignedBaseType) {
+  using RangeVector = RangeVector<int32_t, uint32_t>;
+  using Entry = RangeVector::Entry;
+
+  RangeVector V;
+  V.Append(10, 5);
+  V.Append(-3, 6);
+  V.Append(-10, 3);
+  V.Sort();
+  EXPECT_THAT(V,
+              testing::ElementsAre(Entry(-10, 3), Entry(-3, 6), Entry(10, 5)));
+  Entry e = *V.begin();
+  EXPECT_EQ(e.GetRangeBase(), -10);
+  EXPECT_EQ(e.GetByteSize(), 3u);
+  EXPECT_EQ(e.GetRangeEnd(), -7);
+  EXPECT_TRUE(e.Contains(-10));
+  EXPECT_TRUE(e.Contains(-8));
+  EXPECT_FALSE(e.Contains(-7));
+  EXPECT_TRUE(e.Union(Entry(-8, 2)));
+  EXPECT_EQ(e, Entry(-10, 4));
+  EXPECT_EQ(e.Intersect(Entry(-7, 3)), Entry(-7, 1));
+}
+
 TEST(RangeVector, CombineConsecutiveRanges) {
   using RangeVector = RangeVector<uint32_t, uint32_t>;
   using Entry = RangeVector::Entry;