diff --git a/wpiutil/src/main/native/cpp/leb128.cpp b/wpiutil/src/main/native/cpp/leb128.cpp
index 14fb10400b..aa931c0bb9 100644
--- a/wpiutil/src/main/native/cpp/leb128.cpp
+++ b/wpiutil/src/main/native/cpp/leb128.cpp
@@ -45,7 +45,7 @@ uint64_t ReadUleb128(const char* addr, uint64_t* ret) {
     addr++;
     count++;
 
-    result |= (byte & 0x7f) << shift;
+    result |= (byte & 0x7fULL) << shift;
     shift += 7;
 
     if (!(byte & 0x80)) {
@@ -69,7 +69,7 @@ bool ReadUleb128(raw_istream& is, uint64_t* ret) {
       return false;
     }
 
-    result |= (byte & 0x7f) << shift;
+    result |= (byte & 0x7fULL) << shift;
     shift += 7;
 
     if (!(byte & 0x80)) {
diff --git a/wpiutil/src/test/native/cpp/leb128Test.cpp b/wpiutil/src/test/native/cpp/leb128Test.cpp
index 7b02935dce..cc537ae300 100644
--- a/wpiutil/src/test/native/cpp/leb128Test.cpp
+++ b/wpiutil/src/test/native/cpp/leb128Test.cpp
@@ -45,6 +45,8 @@ TEST(LEB128Test, WriteUleb128) {
   EXPECT_ULEB128_EQ("\xff\x01", 0xff, 0);
   EXPECT_ULEB128_EQ("\x80\x02", 0x100, 0);
   EXPECT_ULEB128_EQ("\x81\x02", 0x101, 0);
+  EXPECT_ULEB128_EQ("\x80\x41", 0x2080, 0);
+  EXPECT_ULEB128_EQ("\x80\xc1\x80\x80\x10", 0x100002080, 0);
 
 #undef EXPECT_ULEB128_EQ
 }
@@ -70,7 +72,8 @@ TEST(LEB128Test, ReadUleb128) {
   EXPECT_READ_ULEB128_EQ(0xffu, "\xff\x01");
   EXPECT_READ_ULEB128_EQ(0x100u, "\x80\x02");
   EXPECT_READ_ULEB128_EQ(0x101u, "\x81\x02");
-  EXPECT_READ_ULEB128_EQ(8320u, "\x80\xc1\x80\x80\x10");
+  EXPECT_READ_ULEB128_EQ(0x2080u, "\x80\x41");
+  EXPECT_READ_ULEB128_EQ(0x100002080u, "\x80\xc1\x80\x80\x10");
 
 #undef EXPECT_READ_ULEB128_EQ
 }