diff --git a/re2/bitmap256.h b/re2/bitmap256.h
index 54c3bf3..4899379 100644
--- a/re2/bitmap256.h
+++ b/re2/bitmap256.h
@@ -32,7 +32,7 @@
     DCHECK_GE(c, 0);
     DCHECK_LE(c, 255);
 
-    return (words_[c / 64] & (1ULL << (c % 64))) != 0;
+    return (words_[c / 64] & (uint64_t{1} << (c % 64))) != 0;
   }
 
   // Sets the bit with index c.
@@ -40,7 +40,7 @@
     DCHECK_GE(c, 0);
     DCHECK_LE(c, 255);
 
-    words_[c / 64] |= (1ULL << (c % 64));
+    words_[c / 64] |= (uint64_t{1} << (c % 64));
   }
 
   // Finds the next non-zero bit with index >= c.
@@ -88,7 +88,7 @@
 
   // Check the word that contains the bit. Mask out any lower bits.
   int i = c / 64;
-  uint64_t word = words_[i] & (~0ULL << (c % 64));
+  uint64_t word = words_[i] & (~uint64_t{0} << (c % 64));
   if (word != 0)
     return (i * 64) + FindLSBSet(word);
 
diff --git a/re2/testing/regexp_benchmark.cc b/re2/testing/regexp_benchmark.cc
index c53ade0..d85784f 100644
--- a/re2/testing/regexp_benchmark.cc
+++ b/re2/testing/regexp_benchmark.cc
@@ -944,7 +944,7 @@
                      bool expect_match) {
   Regexp* re = Regexp::Parse(regexp, Regexp::LikePerl, NULL);
   CHECK(re);
-  Prog* prog = re->CompileToProg(1LL<<31);
+  Prog* prog = re->CompileToProg(int64_t{1}<<31);
   CHECK(prog);
   for (auto _ : state) {
     bool failed = false;