diff --git a/internal/cgen/base/strconv-impl.c b/internal/cgen/base/strconv-impl.c
index 74e990b..3b083a5 100644
--- a/internal/cgen/base/strconv-impl.c
+++ b/internal/cgen/base/strconv-impl.c
@@ -1116,8 +1116,8 @@
   size_t n = len;
 
   while (n--) {
-    *d = (wuffs_base__parse_number__hexadecimal_digits[s[0]] << 4) |
-         (wuffs_base__parse_number__hexadecimal_digits[s[1]] & 0x0F);
+    *d = (uint8_t)((wuffs_base__parse_number__hexadecimal_digits[s[0]] << 4) |
+                   (wuffs_base__parse_number__hexadecimal_digits[s[1]] & 0x0F));
     d += 1;
     s += 2;
   }
@@ -1135,8 +1135,8 @@
   size_t n = len;
 
   while (n--) {
-    *d = (wuffs_base__parse_number__hexadecimal_digits[s[2]] << 4) |
-         (wuffs_base__parse_number__hexadecimal_digits[s[3]] & 0x0F);
+    *d = (uint8_t)((wuffs_base__parse_number__hexadecimal_digits[s[2]] << 4) |
+                   (wuffs_base__parse_number__hexadecimal_digits[s[3]] & 0x0F));
     d += 1;
     s += 4;
   }
diff --git a/internal/cgen/data.go b/internal/cgen/data.go
index 3f35fff..eacdbca 100644
--- a/internal/cgen/data.go
+++ b/internal/cgen/data.go
@@ -114,7 +114,8 @@
 	"man2 >> 52) == 0) {\n      exp2 = bias;\n    }\n\n    // Pack the bits and return.\n    uint64_t exp2_bits = (uint64_t)((exp2 - bias) & 0x07FF);  // (1 << 11) - 1.\n    uint64_t bits = (man2 & 0x000FFFFFFFFFFFFF) |             // (1 << 52) - 1.\n                    (exp2_bits << 52) |                       //\n                    (h.negative ? 0x8000000000000000 : 0);    // (1 << 63).\n\n    wuffs_base__result_f64 ret;\n    ret.status.repr = NULL;\n    ret.value = wuffs_base__ieee_754_bit_representation__to_f64(bits);\n    return ret;\n  } while (0);\n\nzero:\n  do {\n    uint64_t bits = h.negative ? 0x8000000000000000 : 0;\n\n    wuffs_base__result_f64 ret;\n    ret.status.repr = NULL;\n    ret.value = wuffs_base__ieee_754_bit_representation__to_f64(bits);\n    return ret;\n  } while (0);\n\ninfinity:\n  do {\n    uint64_t bits = h.negative ? 0xFFF0000000000000 : 0x7FF0000000000000;\n\n    wuffs_base__result_f64 ret;\n    ret.status.repr = NULL;\n    ret.value = wuffs_base__ieee_754_bit_representation__to_f64(bits);\n    return ret;\n  } whi" +
 	"le (0);\n}\n\n" +
 	"" +
-	"// ---------------- Hexadecimal\n\nsize_t  //\nwuffs_base__hexadecimal__decode2(wuffs_base__slice_u8 dst,\n                                 wuffs_base__slice_u8 src) {\n  size_t src_len2 = src.len / 2;\n  size_t len = dst.len < src_len2 ? dst.len : src_len2;\n  uint8_t* d = dst.ptr;\n  uint8_t* s = src.ptr;\n  size_t n = len;\n\n  while (n--) {\n    *d = (wuffs_base__parse_number__hexadecimal_digits[s[0]] << 4) |\n         (wuffs_base__parse_number__hexadecimal_digits[s[1]] & 0x0F);\n    d += 1;\n    s += 2;\n  }\n\n  return len;\n}\n\nsize_t  //\nwuffs_base__hexadecimal__decode4(wuffs_base__slice_u8 dst,\n                                 wuffs_base__slice_u8 src) {\n  size_t src_len4 = src.len / 4;\n  size_t len = dst.len < src_len4 ? dst.len : src_len4;\n  uint8_t* d = dst.ptr;\n  uint8_t* s = src.ptr;\n  size_t n = len;\n\n  while (n--) {\n    *d = (wuffs_base__parse_number__hexadecimal_digits[s[2]] << 4) |\n         (wuffs_base__parse_number__hexadecimal_digits[s[3]] & 0x0F);\n    d += 1;\n    s += 4;\n  }\n\n  return len;\n}\n\n" +
+	"// ---------------- Hexadecimal\n\nsize_t  //\nwuffs_base__hexadecimal__decode2(wuffs_base__slice_u8 dst,\n                                 wuffs_base__slice_u8 src) {\n  size_t src_len2 = src.len / 2;\n  size_t len = dst.len < src_len2 ? dst.len : src_len2;\n  uint8_t* d = dst.ptr;\n  uint8_t* s = src.ptr;\n  size_t n = len;\n\n  while (n--) {\n    *d = (uint8_t)((wuffs_base__parse_number__hexadecimal_digits[s[0]] << 4) |\n                   (wuffs_base__parse_number__hexadecimal_digits[s[1]] & 0x0F));\n    d += 1;\n    s += 2;\n  }\n\n  return len;\n}\n\nsize_t  //\nwuffs_base__hexadecimal__decode4(wuffs_base__slice_u8 dst,\n                                 wuffs_base__slice_u8 src) {\n  size_t src_len4 = src.len / 4;\n  size_t len = dst.len < src_len4 ? dst.len : src_len4;\n  uint8_t* d = dst.ptr;\n  uint8_t* s = src.ptr;\n  size_t n = len;\n\n  while (n--) {\n    *d = (uint8_t)((wuffs_base__parse_number__hexadecimal_digits[s[2]] << 4) |\n                   (wuffs_base__parse_number__hexadecimal_digits[s[3]] & 0x0F));\n    d += 1;\n    s +" +
+	"= 4;\n  }\n\n  return len;\n}\n\n" +
 	"" +
 	"// ---------------- Unicode and UTF-8\n\nsize_t  //\nwuffs_base__utf_8__encode(wuffs_base__slice_u8 dst, uint32_t code_point) {\n  if (code_point <= 0x7F) {\n    if (dst.len >= 1) {\n      dst.ptr[0] = (uint8_t)(code_point);\n      return 1;\n    }\n\n  } else if (code_point <= 0x07FF) {\n    if (dst.len >= 2) {\n      dst.ptr[0] = (uint8_t)(0xC0 | ((code_point >> 6)));\n      dst.ptr[1] = (uint8_t)(0x80 | ((code_point >> 0) & 0x3F));\n      return 2;\n    }\n\n  } else if (code_point <= 0xFFFF) {\n    if ((dst.len >= 3) && ((code_point < 0xD800) || (0xDFFF < code_point))) {\n      dst.ptr[0] = (uint8_t)(0xE0 | ((code_point >> 12)));\n      dst.ptr[1] = (uint8_t)(0x80 | ((code_point >> 6) & 0x3F));\n      dst.ptr[2] = (uint8_t)(0x80 | ((code_point >> 0) & 0x3F));\n      return 3;\n    }\n\n  } else if (code_point <= 0x10FFFF) {\n    if (dst.len >= 4) {\n      dst.ptr[0] = (uint8_t)(0xF0 | ((code_point >> 18)));\n      dst.ptr[1] = (uint8_t)(0x80 | ((code_point >> 12) & 0x3F));\n      dst.ptr[2] = (uint8_t)(0x80 | ((code_point >> 6) & 0x3" +
 	"F));\n      dst.ptr[3] = (uint8_t)(0x80 | ((code_point >> 0) & 0x3F));\n      return 4;\n    }\n  }\n\n  return 0;\n}\n\n// wuffs_base__utf_8__byte_length_minus_1 is the byte length (minus 1) of a\n// UTF-8 encoded code point, based on the encoding's initial byte.\n//  - 0x00 is 1-byte UTF-8 (ASCII).\n//  - 0x01 is the start of 2-byte UTF-8.\n//  - 0x02 is the start of 3-byte UTF-8.\n//  - 0x03 is the start of 4-byte UTF-8.\n//  - 0x40 is a UTF-8 tail byte.\n//  - 0x80 is invalid UTF-8.\n//\n// RFC 3629 (UTF-8) gives this grammar for valid UTF-8:\n//    UTF8-1      = %x00-7F\n//    UTF8-2      = %xC2-DF UTF8-tail\n//    UTF8-3      = %xE0 %xA0-BF UTF8-tail / %xE1-EC 2( UTF8-tail ) /\n//                  %xED %x80-9F UTF8-tail / %xEE-EF 2( UTF8-tail )\n//    UTF8-4      = %xF0 %x90-BF 2( UTF8-tail ) / %xF1-F3 3( UTF8-tail ) /\n//                  %xF4 %x80-8F 2( UTF8-tail )\n//    UTF8-tail   = %x80-BF\nstatic const uint8_t wuffs_base__utf_8__byte_length_minus_1[256] = {\n    // 0     1     2     3     4     5     6     7\n    // 8     9" +
diff --git a/release/c/wuffs-unsupported-snapshot.c b/release/c/wuffs-unsupported-snapshot.c
index 8d94256..6a002fd 100644
--- a/release/c/wuffs-unsupported-snapshot.c
+++ b/release/c/wuffs-unsupported-snapshot.c
@@ -9695,8 +9695,8 @@
   size_t n = len;
 
   while (n--) {
-    *d = (wuffs_base__parse_number__hexadecimal_digits[s[0]] << 4) |
-         (wuffs_base__parse_number__hexadecimal_digits[s[1]] & 0x0F);
+    *d = (uint8_t)((wuffs_base__parse_number__hexadecimal_digits[s[0]] << 4) |
+                   (wuffs_base__parse_number__hexadecimal_digits[s[1]] & 0x0F));
     d += 1;
     s += 2;
   }
@@ -9714,8 +9714,8 @@
   size_t n = len;
 
   while (n--) {
-    *d = (wuffs_base__parse_number__hexadecimal_digits[s[2]] << 4) |
-         (wuffs_base__parse_number__hexadecimal_digits[s[3]] & 0x0F);
+    *d = (uint8_t)((wuffs_base__parse_number__hexadecimal_digits[s[2]] << 4) |
+                   (wuffs_base__parse_number__hexadecimal_digits[s[3]] & 0x0F));
     d += 1;
     s += 4;
   }