diff --git a/include/rapidjson/internal/diyfp.h b/include/rapidjson/internal/diyfp.h
index 29abf80..cd941fa 100644
--- a/include/rapidjson/internal/diyfp.h
+++ b/include/rapidjson/internal/diyfp.h
@@ -99,6 +99,7 @@ struct DiyFp {
     }
 
     DiyFp Normalize() const {
+        RAPIDJSON_ASSERT(f != 0); // https://stackoverflow.com/a/26809183/291737
 #if defined(_MSC_VER) && defined(_M_AMD64)
         unsigned long index;
         _BitScanReverse64(&index, f);
diff --git a/test/unittest/readertest.cpp b/test/unittest/readertest.cpp
index e530801..c487ff9 100644
--- a/test/unittest/readertest.cpp
+++ b/test/unittest/readertest.cpp
@@ -207,6 +207,7 @@ static void TestParseDouble() {
 
     TEST_DOUBLE(fullPrecision, "0.0", 0.0);
     TEST_DOUBLE(fullPrecision, "-0.0", -0.0); // For checking issue #289
+    TEST_DOUBLE(fullPrecision, "0e100", 0.0); // Normalize() must not invoke __builtin_clzll(0)
     TEST_DOUBLE(fullPrecision, "1.0", 1.0);
     TEST_DOUBLE(fullPrecision, "-1.0", -1.0);
     TEST_DOUBLE(fullPrecision, "1.5", 1.5);