diff --git a/src/asm/lexer.cpp b/src/asm/lexer.cpp
index ef697813..391b7f70 100644
--- a/src/asm/lexer.cpp
+++ b/src/asm/lexer.cpp
@@ -970,8 +970,8 @@ static std::tuple<uint32_t, uint32_t, bool> readFractionDigits() {
 			prevWasSeparator = true;
 		} else if (isDigit(c)) {
 			prevWasSeparator = false;
-			c -= '0';
-			if (dividend > (UINT32_MAX - c) / 10 || divisor > UINT32_MAX / 10) {
+			int digit = c - '0';
+			if (dividend > (UINT32_MAX - digit) / 10 || divisor > UINT32_MAX / 10) {
 				warning(
 				    WARNING_LARGE_CONSTANT, "Fixed-point constant has too many fractional digits"
 				);
@@ -979,7 +979,7 @@ static std::tuple<uint32_t, uint32_t, bool> readFractionDigits() {
 				for (int d = peek(); isDigit(d) || d == '_'; c = d, d = nextChar()) {}
 				return {dividend, divisor, c == '_'};
 			}
-			dividend = dividend * 10 + c;
+			dividend = dividend * 10 + digit;
 			divisor *= 10;
 		} else {
 			break;
@@ -1000,15 +1000,15 @@ static uint8_t readPrecisionSuffix() {
 	// '_' is not allowed after 'q'/'Q'
 	for (int c = peek(); isDigit(c); c = nextChar()) {
 		empty = false;
-		c -= '0';
-		if (precision > (UINT8_MAX - c) / 10) {
+		int digit = c - '0';
+		if (precision > (UINT8_MAX - digit) / 10) {
 			// Discard any additional digits
 			skipChars(isDigit);
 			// Return an invalid precision to cause a subsequent error, which is checked afterwards
 			// to cover the default `options.fixPrecision` as well, just in case
 			return UINT8_MAX;
 		}
-		precision = precision * 10 + c;
+		precision = precision * 10 + digit;
 	}
 
 	if (empty) {
@@ -1093,7 +1093,7 @@ void lexer_SetGfxDigits(char const digits[4]) {
 }
 
 static uint32_t readBinaryNumber(char const *prefix) {
-	uint32_t value = 0;
+	uint32_t number = 0;
 	bool empty = true;
 	bool prevWasSeparator = false;
 
@@ -1115,21 +1115,21 @@ static uint32_t readBinaryNumber(char const *prefix) {
 		empty = false;
 		prevWasSeparator = false;
 
-		if (value > (UINT32_MAX - bit) / 2) {
+		if (number > (UINT32_MAX - bit) / 2) {
 			warning(WARNING_LARGE_CONSTANT, "Integer constant is too large");
 			// Discard any additional digits
 			skipChars([](int d) { return isCustomBinDigit(d) || d == '_'; });
 			return 0;
 		}
-		value = value * 2 + bit;
+		number = number * 2 + bit;
 	}
 
 	checkDigitsEnding(empty, prefix, prevWasSeparator, "integer");
-	return value;
+	return number;
 }
 
 static uint32_t readOctalNumber(char const *prefix) {
-	uint32_t value = 0;
+	uint32_t number = 0;
 	bool empty = true;
 	bool prevWasSeparator = false;
 
@@ -1143,26 +1143,26 @@ static uint32_t readOctalNumber(char const *prefix) {
 		if (!isOctDigit(c)) {
 			break;
 		}
-		c -= '0';
+		int digit = c - '0';
 		empty = false;
 		prevWasSeparator = false;
 
-		if (value > (UINT32_MAX - c) / 8) {
+		if (number > (UINT32_MAX - digit) / 8) {
 			warning(WARNING_LARGE_CONSTANT, "Integer constant is too large");
 			// Discard any additional digits
 			skipChars([](int d) { return isOctDigit(d) || d == '_'; });
 			return 0;
 		}
-		value = value * 8 + c;
+		number = number * 8 + digit;
 	}
 
 	checkDigitsEnding(empty, prefix, prevWasSeparator, "integer");
-	return value;
+	return number;
 }
 
 static uint32_t readDecimalNumber(int initial) {
 	assume(isDigit(initial));
-	uint32_t value = initial - '0';
+	uint32_t number = initial - '0';
 	bool prevWasSeparator = false;
 
 	for (int c = peek();; c = nextChar()) {
@@ -1175,24 +1175,24 @@ static uint32_t readDecimalNumber(int initial) {
 		if (!isDigit(c)) {
 			break;
 		}
-		c -= '0';
+		int digit = c - '0';
 		prevWasSeparator = false;
 
-		if (value > (UINT32_MAX - c) / 10) {
+		if (number > (UINT32_MAX - digit) / 10) {
 			warning(WARNING_LARGE_CONSTANT, "Integer constant is too large");
 			// Discard any additional digits
 			skipChars([](int d) { return isDigit(d) || d == '_'; });
 			return 0;
 		}
-		value = value * 10 + c;
+		number = number * 10 + digit;
 	}
 
 	checkDigitsEnding(false, nullptr, prevWasSeparator, "integer");
-	return value;
+	return number;
 }
 
 static uint32_t readHexNumber(char const *prefix) {
-	uint32_t value = 0;
+	uint32_t number = 0;
 	bool empty = true;
 	bool prevWasSeparator = false;
 
@@ -1210,17 +1210,17 @@ static uint32_t readHexNumber(char const *prefix) {
 		empty = false;
 		prevWasSeparator = false;
 
-		if (value > (UINT32_MAX - c) / 16) {
+		if (number > (UINT32_MAX - c) / 16) {
 			warning(WARNING_LARGE_CONSTANT, "Integer constant is too large");
 			// Discard any additional digits
 			skipChars([](int d) { return isHexDigit(d) || d == '_'; });
 			return 0;
 		}
-		value = value * 16 + c;
+		number = number * 16 + c;
 	}
 
 	checkDigitsEnding(empty, prefix, prevWasSeparator, "integer");
-	return value;
+	return number;
 }
 
 static uint32_t readGfxConstant() {
@@ -2169,9 +2169,8 @@ static Token skipToLeadingKeyword() {
 			if (int c = skipChars(isBlankSpace); c == EOF) {
 				return Token(T_(YYEOF));
 			} else if (isLetter(c)) {
-				shiftChar();
 				std::string keyword(1, c);
-				for (c = peek(); continuesIdentifier(c); c = nextChar()) {
+				for (c = nextChar(); continuesIdentifier(c); c = nextChar()) {
 					keyword += c;
 				}
 				if (auto search = keywords.find(keyword); search != keywords.end()) {
diff --git a/src/link/lexer.cpp b/src/link/lexer.cpp
index def7c947..a6f59c8d 100644
--- a/src/link/lexer.cpp
+++ b/src/link/lexer.cpp
@@ -84,24 +84,23 @@ static yy::parser::symbol_type yywrap() {
 	return yy::parser::make_YYEOF();
 }
 
-static std::string readKeyword(int c) {
+static std::string readKeyword(int initial) {
 	LexerStackEntry &context = lexerStack.back();
 	std::string keyword;
-	keyword.push_back(c);
-	for (c = context.file.sgetc(); isAlphanumeric(c); c = context.file.snextc()) {
+	keyword.push_back(initial);
+	for (int c = context.file.sgetc(); isAlphanumeric(c); c = context.file.snextc()) {
 		keyword.push_back(c);
 	}
 	return keyword;
 }
 
-static yy::parser::symbol_type parseDecNumber(int c) {
+static yy::parser::symbol_type parseDecNumber(int initial) {
 	LexerStackEntry &context = lexerStack.back();
-	uint32_t number = c - '0';
-	for (c = context.file.sgetc(); isDigit(c) || c == '_'; c = context.file.sgetc()) {
+	uint32_t number = initial - '0';
+	for (int c = context.file.sgetc(); isDigit(c) || c == '_'; c = context.file.snextc()) {
 		if (c != '_') {
 			number = number * 10 + (c - '0');
 		}
-		context.file.sbumpc();
 	}
 	return yy::parser::make_number(number);
 }
@@ -115,12 +114,10 @@ static yy::parser::symbol_type parseBinNumber(char const *prefix) {
 	}
 
 	uint32_t number = c - '0';
-	context.file.sbumpc();
-	for (c = context.file.sgetc(); isBinDigit(c) || c == '_'; c = context.file.sgetc()) {
+	for (c = context.file.snextc(); isBinDigit(c) || c == '_'; c = context.file.snextc()) {
 		if (c != '_') {
 			number = number * 2 + (c - '0');
 		}
-		context.file.sbumpc();
 	}
 	return yy::parser::make_number(number);
 }
@@ -134,12 +131,10 @@ static yy::parser::symbol_type parseOctNumber(char const *prefix) {
 	}
 
 	uint32_t number = c - '0';
-	context.file.sbumpc();
-	for (c = context.file.sgetc(); isOctDigit(c) || c == '_'; c = context.file.sgetc()) {
+	for (c = context.file.snextc(); isOctDigit(c) || c == '_'; c = context.file.snextc()) {
 		if (c != '_') {
 			number = number * 8 + (c - '0');
 		}
-		context.file.sbumpc();
 	}
 	return yy::parser::make_number(number);
 }
@@ -153,41 +148,33 @@ static yy::parser::symbol_type parseHexNumber(char const *prefix) {
 	}
 
 	uint32_t number = parseHexDigit(c);
-	context.file.sbumpc();
-	for (c = context.file.sgetc(); isHexDigit(c) || c == '_'; c = context.file.sgetc()) {
+	for (c = context.file.snextc(); isHexDigit(c) || c == '_'; c = context.file.snextc()) {
 		if (c != '_') {
 			number = number * 16 + parseHexDigit(c);
 		}
-		context.file.sbumpc();
 	}
 	return yy::parser::make_number(number);
 }
 
-static yy::parser::symbol_type parseAnyNumber(int c) {
+static yy::parser::symbol_type parseAnyNumber(int initial) {
 	LexerStackEntry &context = lexerStack.back();
-	if (c == '0') {
+	if (initial == '0') {
 		switch (context.file.sgetc()) {
 		case 'x':
-			context.file.sbumpc();
-			return parseHexNumber("\"0x\"");
 		case 'X':
 			context.file.sbumpc();
-			return parseHexNumber("\"0X\"");
+			return parseHexNumber("\"0x\"");
 		case 'o':
-			context.file.sbumpc();
-			return parseOctNumber("\"0o\"");
 		case 'O':
 			context.file.sbumpc();
-			return parseOctNumber("\"0O\"");
+			return parseOctNumber("\"0o\"");
 		case 'b':
-			context.file.sbumpc();
-			return parseBinNumber("\"0b\"");
 		case 'B':
 			context.file.sbumpc();
-			return parseBinNumber("\"0B");
+			return parseBinNumber("\"0b\"");
 		}
 	}
-	return parseDecNumber(c);
+	return parseDecNumber(initial);
 }
 
 static yy::parser::symbol_type parseString() {
@@ -294,12 +281,7 @@ yy::parser::symbol_type yylex() {
 	} else {
 		scriptError("Unexpected character %s", printChar(c));
 		// Keep reading characters until the EOL, to avoid reporting too many errors.
-		for (c = context.file.sgetc(); !isNewline(c); c = context.file.sgetc()) {
-			if (c == EOF) {
-				break;
-			}
-			context.file.sbumpc();
-		}
+		for (c = context.file.sgetc(); c != EOF && !isNewline(c); c = context.file.snextc()) {}
 		return yylex();
 	}
 	// Not marking as unreachable; this will generate a warning if any codepath forgets to return.