diff --git a/yarp/regexp.c b/yarp/regexp.c
index c8aeaa0adb..4855859442 100644
--- a/yarp/regexp.c
+++ b/yarp/regexp.c
@@ -281,7 +281,9 @@ typedef enum {
 #define YP_REGEXP_OPTION_STATE_SLOTS (YP_REGEXP_OPTION_STATE_SLOT_MAXIMUM - YP_REGEXP_OPTION_STATE_SLOT_MINIMUM + 1)
 
 // This is the set of options that are configurable on the regular expression.
-typedef struct { unsigned char values[YP_REGEXP_OPTION_STATE_SLOTS]; } yp_regexp_options_t;
+typedef struct {
+    unsigned char values[YP_REGEXP_OPTION_STATE_SLOTS];
+} yp_regexp_options_t;
 
 // Initialize a new set of options to their default values.
 static void
@@ -300,7 +302,7 @@ yp_regexp_options_init(yp_regexp_options_t *options) {
 static bool
 yp_regexp_options_add(yp_regexp_options_t *options, unsigned char key) {
     if (key >= YP_REGEXP_OPTION_STATE_SLOT_MINIMUM && key <= YP_REGEXP_OPTION_STATE_SLOT_MAXIMUM) {
-        key -= YP_REGEXP_OPTION_STATE_SLOT_MINIMUM;
+        key = (unsigned char) (key - YP_REGEXP_OPTION_STATE_SLOT_MINIMUM);
 
         switch (options->values[key]) {
             case YP_REGEXP_OPTION_STATE_INVALID:
@@ -323,7 +325,7 @@ yp_regexp_options_add(yp_regexp_options_t *options, unsigned char key) {
 static bool
 yp_regexp_options_remove(yp_regexp_options_t *options, unsigned char key) {
     if (key >= YP_REGEXP_OPTION_STATE_SLOT_MINIMUM && key <= YP_REGEXP_OPTION_STATE_SLOT_MAXIMUM) {
-        key -= YP_REGEXP_OPTION_STATE_SLOT_MINIMUM;
+        key = (unsigned char) (key - YP_REGEXP_OPTION_STATE_SLOT_MINIMUM);
 
         switch (options->values[key]) {
             case YP_REGEXP_OPTION_STATE_INVALID:
diff --git a/yarp/unescape.c b/yarp/unescape.c
index 5370b27355..296caf01aa 100644
--- a/yarp/unescape.c
+++ b/yarp/unescape.c
@@ -64,19 +64,19 @@ unescape_octal(const char *backslash, unsigned char *value) {
         return 2;
     }
 
-    *value = (*value << 3) | (backslash[2] - '0');
+    *value = (unsigned char) ((*value << 3) | (backslash[2] - '0'));
     if (!yp_char_is_octal_digit(backslash[3])) {
         return 3;
     }
 
-    *value = (*value << 3) | (backslash[3] - '0');
+    *value = (unsigned char) ((*value << 3) | (backslash[3] - '0'));
     return 4;
 }
 
 // Convert a hexadecimal digit into its equivalent value.
 static inline unsigned char
 unescape_hexadecimal_digit(const char value) {
-    return (value <= '9') ? (unsigned char) (value - '0') : (value & 0x7) + 9;
+    return (unsigned char) ((value <= '9') ? (value - '0') : (value & 0x7) + 9);
 }
 
 // Scan the 1-2 digits of hexadecimal into the value. Returns the number of
@@ -88,7 +88,7 @@ unescape_hexadecimal(const char *backslash, unsigned char *value) {
         return 3;
     }
 
-    *value = (*value << 4) | unescape_hexadecimal_digit(backslash[3]);
+    *value = (unsigned char) ((*value << 4) | unescape_hexadecimal_digit(backslash[3]));
     return 4;
 }
 
@@ -113,22 +113,22 @@ unescape_unicode_write(char *dest, uint32_t value, const char *start, const char
 
     if (value <= 0x7F) {
         // 0xxxxxxx
-        bytes[0] = value;
+        bytes[0] = (unsigned char) value;
         return 1;
     }
 
     if (value <= 0x7FF) {
         // 110xxxxx 10xxxxxx
-        bytes[0] = 0xC0 | (value >> 6);
-        bytes[1] = 0x80 | (value & 0x3F);
+        bytes[0] = (unsigned char) (0xC0 | (value >> 6));
+        bytes[1] = (unsigned char) (0x80 | (value & 0x3F));
         return 2;
     }
 
     if (value <= 0xFFFF) {
         // 1110xxxx 10xxxxxx 10xxxxxx
-        bytes[0] = 0xE0 | (value >> 12);
-        bytes[1] = 0x80 | ((value >> 6) & 0x3F);
-        bytes[2] = 0x80 | (value & 0x3F);
+        bytes[0] = (unsigned char) (0xE0 | (value >> 12));
+        bytes[1] = (unsigned char) (0x80 | ((value >> 6) & 0x3F));
+        bytes[2] = (unsigned char) (0x80 | (value & 0x3F));
         return 3;
     }
 
@@ -136,10 +136,10 @@ unescape_unicode_write(char *dest, uint32_t value, const char *start, const char
     // the input is invalid.
     if (value <= 0x10FFFF) {
         // 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
-        bytes[0] = 0xF0 | (value >> 18);
-        bytes[1] = 0x80 | ((value >> 12) & 0x3F);
-        bytes[2] = 0x80 | ((value >> 6) & 0x3F);
-        bytes[3] = 0x80 | (value & 0x3F);
+        bytes[0] = (unsigned char) (0xF0 | (value >> 18));
+        bytes[1] = (unsigned char) (0x80 | ((value >> 12) & 0x3F));
+        bytes[2] = (unsigned char) (0x80 | ((value >> 6) & 0x3F));
+        bytes[3] = (unsigned char) (0x80 | (value & 0x3F));
         return 4;
     }
 
diff --git a/yarp/util/yp_char.c b/yarp/util/yp_char.c
index 1c0c20edd9..d27a04104e 100644
--- a/yarp/util/yp_char.c
+++ b/yarp/util/yp_char.c
@@ -75,7 +75,7 @@ yp_strspn_whitespace(const char *string, ptrdiff_t length) {
 // whitespace while also tracking the location of each newline. Disallows
 // searching past the given maximum number of characters.
 size_t
-yp_strspn_whitespace_newlines(const char *string, long length, yp_newline_list_t *newline_list, bool stop_at_newline) {
+yp_strspn_whitespace_newlines(const char *string, ptrdiff_t length, yp_newline_list_t *newline_list, bool stop_at_newline) {
     if (length <= 0) return 0;
 
     size_t size = 0;
diff --git a/yarp/util/yp_char.h b/yarp/util/yp_char.h
index dcc011f0a1..010d34d669 100644
--- a/yarp/util/yp_char.h
+++ b/yarp/util/yp_char.h
@@ -15,7 +15,7 @@ size_t yp_strspn_whitespace(const char *string, ptrdiff_t length);
 // whitespace while also tracking the location of each newline. Disallows
 // searching past the given maximum number of characters.
 size_t
-yp_strspn_whitespace_newlines(const char *string, long length, yp_newline_list_t *newline_list, bool);
+yp_strspn_whitespace_newlines(const char *string, ptrdiff_t length, yp_newline_list_t *newline_list, bool);
 
 // Returns the number of characters at the start of the string that are inline
 // whitespace. Disallows searching past the given maximum number of characters.
diff --git a/yarp/util/yp_constant_pool.c b/yarp/util/yp_constant_pool.c
index 8c1889c6b4..fdece2dabb 100644
--- a/yarp/util/yp_constant_pool.c
+++ b/yarp/util/yp_constant_pool.c
@@ -110,7 +110,7 @@ yp_constant_pool_init(yp_constant_pool_t *pool, size_t capacity) {
 // if any potential calls to resize fail.
 yp_constant_id_t
 yp_constant_pool_insert(yp_constant_pool_t *pool, const char *start, size_t length) {
-    if (pool->size >= pool->capacity * 0.75) {
+    if (pool->size >= (pool->capacity / 4 * 3)) {
         if (!yp_constant_pool_resize(pool)) return 0;
     }
 
diff --git a/yarp/yarp.c b/yarp/yarp.c
index f8301daa6b..f831d03ee1 100644
--- a/yarp/yarp.c
+++ b/yarp/yarp.c
@@ -5929,7 +5929,7 @@ parser_lex(yp_parser_t *parser) {
                                 }
 
                                 size_t ident_length = (size_t) (parser->current.end - ident_start);
-                                if (quote != YP_HEREDOC_QUOTE_NONE && !match(parser, quote)) {
+                                if (quote != YP_HEREDOC_QUOTE_NONE && !match(parser, (char) quote)) {
                                     // TODO: handle unterminated heredoc
                                 }