diff --git a/checkers/hexLiteral_checker.go b/checkers/hexLiteral_checker.go
new file mode 100644
index 000000000..8216417a8
--- /dev/null
+++ b/checkers/hexLiteral_checker.go
@@ -0,0 +1,60 @@
+package checkers
+
+import (
+	"go/ast"
+	"go/token"
+	"strings"
+
+	"github.com/go-lintpack/lintpack"
+	"github.com/go-lintpack/lintpack/astwalk"
+	"github.com/go-toolsmith/astcast"
+)
+
+func init() {
+	var info lintpack.CheckerInfo
+	info.Name = "hexLiteral"
+	info.Tags = []string{"style", "experimental"}
+	info.Summary = ""
+	info.Before = `
+x := 0X12
+y := 0xfF`
+	info.After = `
+x := 0x12
+// (A)
+y := 0xff
+// (B)
+y := 0xFF`
+
+	collection.AddChecker(&info, func(ctx *lintpack.CheckerContext) lintpack.FileWalker {
+		return astwalk.WalkerForExpr(&hexLiteralChecker{ctx: ctx})
+	})
+}
+
+type hexLiteralChecker struct {
+	astwalk.WalkHandler
+	ctx *lintpack.CheckerContext
+}
+
+func (c *hexLiteralChecker) warn0X(lit *ast.BasicLit) {
+	suggest := "0x" + lit.Value[len("0X"):]
+	c.ctx.Warn(lit, "prefer 0x over 0X, s/%s/%s/", lit.Value, suggest)
+}
+
+func (c *hexLiteralChecker) warnMixedDigits(lit *ast.BasicLit) {
+	c.ctx.Warn(lit, "don't mix hex literal letter digits casing")
+}
+
+func (c *hexLiteralChecker) VisitExpr(expr ast.Expr) {
+	lit := astcast.ToBasicLit(expr)
+	if lit.Kind != token.INT || len(lit.Value) < 3 {
+		return
+	}
+	if strings.HasPrefix(lit.Value, "0X") {
+		c.warn0X(lit)
+		return
+	}
+	digits := lit.Value[len("0x"):]
+	if strings.ToLower(digits) != digits && strings.ToUpper(digits) != digits {
+		c.warnMixedDigits(lit)
+	}
+}
diff --git a/checkers/hexLiterals_checker.go b/checkers/hexLiterals_checker.go
deleted file mode 100644
index 6f24b2980..000000000
--- a/checkers/hexLiterals_checker.go
+++ /dev/null
@@ -1,94 +0,0 @@
-package checkers
-
-import (
-	"go/ast"
-	"strings"
-	"unicode"
-
-	"github.com/go-lintpack/lintpack"
-	"github.com/go-lintpack/lintpack/astwalk"
-	"github.com/go-toolsmith/astcast"
-	"github.com/go-toolsmith/astp"
-)
-
-func init() {
-	var info lintpack.CheckerInfo
-	info.Name = "hexLiterals"
-	info.Tags = []string{"style", "experimental"}
-	info.Summary = ""
-	info.Before = `
-x := 0X12
-y := 0xfF`
-	info.After = `
-x := 0x12
-// (A)
-y := 0xff
-// (B)
-y := 0xFF`
-
-	collection.AddChecker(&info, func(ctx *lintpack.CheckerContext) lintpack.FileWalker {
-		return astwalk.WalkerForExpr(&hexLiteralChecker{ctx: ctx})
-	})
-}
-
-type hexLiteralChecker struct {
-	astwalk.WalkHandler
-	ctx *lintpack.CheckerContext
-}
-
-func (c *hexLiteralChecker) VisitExpr(expr ast.Expr) {
-	if !astp.IsBasicLit(expr) {
-		return
-	}
-	v := astcast.ToBasicLit(expr)
-
-	if !strings.HasPrefix(v.Value, "0X") && !strings.HasPrefix(v.Value, "0x") {
-		return
-	}
-
-	prefix := v.Value[:2]
-	value := v.Value[2:]
-
-	switch prefix {
-	case "0X":
-		if isAnyLetter(value) {
-			if isGoodHex(value) {
-				c.ctx.Warn(expr, "Should be 0x%s", value)
-				return
-			}
-			c.ctx.Warn(expr,
-				"Should be 0x%s or 0x%s",
-				strings.ToLower(value),
-				strings.ToUpper(value))
-			return
-		}
-
-		c.ctx.Warn(expr, "Should be 0x%s", value)
-	case "0x":
-		if isAnyLetter(value) {
-			if isGoodHex(value) {
-				return
-			}
-			c.ctx.Warn(expr,
-				"Should be 0x%s or 0x%s",
-				strings.ToLower(value),
-				strings.ToUpper(value))
-			return
-		}
-
-		c.ctx.Warn(expr, "Should be 0x%s", value)
-	}
-}
-
-func isAnyLetter(s string) bool {
-	for _, r := range s {
-		if unicode.IsLetter(r) {
-			return true
-		}
-	}
-	return false
-}
-
-func isGoodHex(value string) bool {
-	return value == strings.ToLower(value) || value == strings.ToUpper(value)
-}
diff --git a/checkers/testdata/hexLiteral/negative_tests.go b/checkers/testdata/hexLiteral/negative_tests.go
new file mode 100644
index 000000000..dcc1bd224
--- /dev/null
+++ b/checkers/testdata/hexLiteral/negative_tests.go
@@ -0,0 +1,23 @@
+package checker_test
+
+func negatives() {
+	_ = 0xFF
+	_ = 0xff
+	_ = "0xfF"
+}
+
+func noLetters() {
+	_ = 0x11
+	_ = 0x0
+}
+
+func digitsAndLetters() {
+	_ = 0x1aa
+	_ = 0x1AA
+}
+
+func decimals() {
+	_ = 1
+	_ = 10
+	_ = 12345
+}
diff --git a/checkers/testdata/hexLiteral/positive_tests.go b/checkers/testdata/hexLiteral/positive_tests.go
new file mode 100644
index 000000000..da62101a9
--- /dev/null
+++ b/checkers/testdata/hexLiteral/positive_tests.go
@@ -0,0 +1,23 @@
+package checker_test
+
+func bad0X() {
+	/*! prefer 0x over 0X, s/0X12/0x12/ */
+	_ = 0X12
+	/*! prefer 0x over 0X, s/0XEE/0xEE/ */
+	_ = 0XEE
+	/*! prefer 0x over 0X, s/0Xaa/0xaa/ */
+	_ = 0Xaa
+}
+
+func mixedLetterDigits() {
+	/*! don't mix hex literal letter digits casing */
+	_ = 0xfF
+	/*! don't mix hex literal letter digits casing */
+	_ = 0xFf
+	/*! don't mix hex literal letter digits casing */
+	_ = 0x11f0F
+	/*! don't mix hex literal letter digits casing */
+	_ = 0xff11FF
+	/*! don't mix hex literal letter digits casing */
+	_ = 0xabcdE
+}
diff --git a/checkers/testdata/hexLiterals/negative_tests.go b/checkers/testdata/hexLiterals/negative_tests.go
deleted file mode 100644
index 4ebac8dff..000000000
--- a/checkers/testdata/hexLiterals/negative_tests.go
+++ /dev/null
@@ -1,7 +0,0 @@
-package checker_test
-
-func negatives() {
-	_ = 0xFF
-	_ = 0xff
-	_ = "0xfF"
-}
diff --git a/checkers/testdata/hexLiterals/positive_tests.go b/checkers/testdata/hexLiterals/positive_tests.go
deleted file mode 100644
index 407a919ed..000000000
--- a/checkers/testdata/hexLiterals/positive_tests.go
+++ /dev/null
@@ -1,15 +0,0 @@
-package checker_test
-
-func someTest() {
-	/*! Should be 0x12 */
-	_ = 0X12
-
-	/*! Should be 0xff or 0xFF */
-	_ = 0xfF
-
-	/*! Should be 0xEE */
-	_ = 0XEE
-
-	/*! Should be 0xaa */
-	_ = 0Xaa
-}