diff --git a/libc/src/__support/UInt.h b/libc/src/__support/UInt.h
--- a/libc/src/__support/UInt.h
+++ b/libc/src/__support/UInt.h
@@ -381,7 +381,7 @@
 
     BigInt<Bits, Signed> quotient(0);
     BigInt<Bits, Signed> subtractor = other;
-    int cur_bit = subtractor.clz() - this->clz();
+    int cur_bit = static_cast<int>(subtractor.clz() - this->clz());
     subtractor.shift_left(cur_bit);
 
     for (; cur_bit >= 0 && *this > 0; --cur_bit, subtractor.shift_right(1)) {
diff --git a/libc/src/__support/str_to_float.h b/libc/src/__support/str_to_float.h
--- a/libc/src/__support/str_to_float.h
+++ b/libc/src/__support/str_to_float.h
@@ -1196,7 +1196,7 @@
             if (strtoint_result.has_error()) {
               error = strtoint_result.error;
             }
-            nan_mantissa = strtoint_result.value;
+            nan_mantissa = static_cast<BitsType>(strtoint_result.value);
             if (src[left_paren + 1 + strtoint_result.parsed_len] != ')')
               nan_mantissa = 0;
           }