diff --git a/double-conversion/string-to-double.cc b/double-conversion/string-to-double.cc
index d7f7a4a..12b88f9 100644
--- a/double-conversion/string-to-double.cc
+++ b/double-conversion/string-to-double.cc
@@ -441,11 +441,6 @@
     }
   }
 
-  // The longest form of simplified number is: "-<significant digits>.1eXXX\0".
-  const int kBufferSize = kMaxSignificantDigits + 10;
-  char buffer[kBufferSize];  // NOLINT: size is known at compile time.
-  int buffer_pos = 0;
-
   // Exponent will be adjusted if insignificant digits of the integer part
   // or insignificant leading zeros of the fractional part are dropped.
   int exponent = 0;
@@ -480,7 +475,6 @@
         return junk_string_value_;
       }
 
-      DOUBLE_CONVERSION_ASSERT(buffer_pos == 0);
       *processed_characters_count = static_cast<int>(current - input);
       return sign ? -Double::Infinity() : Double::Infinity();
     }
@@ -499,7 +493,6 @@
         return junk_string_value_;
       }
 
-      DOUBLE_CONVERSION_ASSERT(buffer_pos == 0);
       *processed_characters_count = static_cast<int>(current - input);
       return sign ? -Double::NaN() : Double::NaN();
     }
@@ -556,6 +549,12 @@
 
   bool octal = leading_zero && (flags_ & ALLOW_OCTALS) != 0;
 
+  // The longest form of simplified number is: "-<significant digits>.1eXXX\0".
+  const int kBufferSize = kMaxSignificantDigits + 10;
+  DOUBLE_CONVERSION_STACK_UNINITIALIZED char
+      buffer[kBufferSize];  // NOLINT: size is known at compile time.
+  int buffer_pos = 0;
+
   // Copy significant digits of the integer part (if any) to the buffer.
   while (*current >= '0' && *current <= '9') {
     if (significant_digits < kMaxSignificantDigits) {
diff --git a/double-conversion/utils.h b/double-conversion/utils.h
index 5393baa..471c3da 100644
--- a/double-conversion/utils.h
+++ b/double-conversion/utils.h
@@ -64,6 +64,12 @@
 #endif
 #endif
 
+#if defined(__clang__) && __has_attribute(uninitialized)
+#define DOUBLE_CONVERSION_STACK_UNINITIALIZED __attribute__((uninitialized))
+#else
+#define DOUBLE_CONVERSION_STACK_UNINITIALIZED
+#endif
+
 // Double operations detection based on target architecture.
 // Linux uses a 80bit wide floating point stack on x86. This induces double
 // rounding, which in turn leads to wrong results.