diff --git a/import_obfuscation.go b/import_obfuscation.go
index 16f6cef..8e69298 100644
--- a/import_obfuscation.go
+++ b/import_obfuscation.go
@@ -418,13 +418,13 @@ func newPrivateName(name, path string) (privateName, bool) {
 }
 
 func dedupStrings(paths []string) []string {
-	seen := make(map[string]struct{}, len(paths))
+	seen := make(map[string]bool, len(paths))
 	j := 0
 	for _, v := range paths {
-		if _, ok := seen[v]; ok {
+		if seen[v] {
 			continue
 		}
-		seen[v] = struct{}{}
+		seen[v] = true
 		paths[j] = v
 		j++
 	}
@@ -432,14 +432,14 @@ func dedupStrings(paths []string) []string {
 }
 
 func dedupPrivateNames(names []privateName) []privateName {
-	seen := make(map[string]struct{}, len(names))
+	seen := make(map[string]bool, len(names))
 	j := 0
 	for _, v := range names {
 		combined := v.name + string(v.seed)
-		if _, ok := seen[combined]; ok {
+		if seen[combined] {
 			continue
 		}
-		seen[combined] = struct{}{}
+		seen[combined] = true
 		names[j] = v
 		j++
 	}
diff --git a/internal/literals/literals.go b/internal/literals/literals.go
index 8e67918..b1f793b 100644
--- a/internal/literals/literals.go
+++ b/internal/literals/literals.go
@@ -21,7 +21,7 @@ func randObfuscator() obfuscator {
 }
 
 // Obfuscate replace literals with obfuscated lambda functions
-func Obfuscate(files []*ast.File, info *types.Info, fset *token.FileSet, blacklist map[types.Object]struct{}) []*ast.File {
+func Obfuscate(files []*ast.File, info *types.Info, fset *token.FileSet, blacklist map[types.Object]bool) []*ast.File {
 	pre := func(cursor *astutil.Cursor) bool {
 		switch x := cursor.Node().(type) {
 		case *ast.GenDecl:
@@ -49,7 +49,7 @@ func Obfuscate(files []*ast.File, info *types.Info, fset *token.FileSet, blackli
 					}
 
 					// The object itself is blacklisted, e.g. a value that needs to be constant
-					if _, ok := blacklist[obj]; ok {
+					if blacklist[obj] {
 						return false
 					}
 				}
@@ -209,7 +209,7 @@ func obfuscateByteArray(data []byte, length int64) *ast.CallExpr {
 }
 
 // ConstBlacklist blacklist identifieres used in constant expressions
-func ConstBlacklist(node ast.Node, info *types.Info, blacklist map[types.Object]struct{}) {
+func ConstBlacklist(node ast.Node, info *types.Info, blacklist map[types.Object]bool) {
 	blacklistObjects := func(node ast.Node) bool {
 		ident, ok := node.(*ast.Ident)
 		if !ok {
@@ -217,7 +217,7 @@ func ConstBlacklist(node ast.Node, info *types.Info, blacklist map[types.Object]
 		}
 
 		obj := info.ObjectOf(ident)
-		blacklist[obj] = struct{}{}
+		blacklist[obj] = true
 
 		return true
 	}
diff --git a/main.go b/main.go
index 3fe70dc..9df81d7 100644
--- a/main.go
+++ b/main.go
@@ -456,7 +456,7 @@ func transformCompile(args []string) ([]string, error) {
 			// The local name must not be obfuscated.
 			obj := tf.pkg.Scope().Lookup(localName)
 			if obj != nil {
-				tf.blacklist[obj] = struct{}{}
+				tf.blacklist[obj] = true
 			}
 
 			// If the new name is of the form "pkgpath.Name", and
@@ -762,7 +762,7 @@ func fillBuildInfo(flags []string) error {
 //
 // The blacklist mainly contains named types and their field declarations.
 func (tf *transformer) buildBlacklist(files []*ast.File) {
-	tf.blacklist = make(map[types.Object]struct{})
+	tf.blacklist = make(map[types.Object]bool)
 
 	reflectBlacklist := func(node ast.Node) bool {
 		expr, _ := node.(ast.Expr) // info.TypeOf(nil) will just return nil
@@ -814,11 +814,11 @@ func (tf *transformer) buildBlacklist(files []*ast.File) {
 
 // collectNames collects all names, including the names of local variables,
 // functions, global fields, etc.
-func collectNames(files []*ast.File) map[string]struct{} {
-	blacklist := make(map[string]struct{})
+func collectNames(files []*ast.File) map[string]bool {
+	blacklist := make(map[string]bool)
 	visit := func(node ast.Node) bool {
 		if ident, ok := node.(*ast.Ident); ok {
-			blacklist[ident.Name] = struct{}{}
+			blacklist[ident.Name] = true
 		}
 		return true
 	}
@@ -838,9 +838,9 @@ type transformer struct {
 	// Maps to keep track of how, or whether not, we should obfuscate
 	// certain parts of the package.
 	// TODO: document better and use better field names; see issue #169.
-	blacklist      map[types.Object]struct{}
+	blacklist      map[types.Object]bool
 	privateNameMap map[string]string
-	existingNames  map[string]struct{}
+	existingNames  map[string]bool
 
 	// nameCounter keeps track of how many unique identifier names we've
 	// obfuscated, so that the obfuscated names get assigned incrementing
@@ -909,7 +909,7 @@ func (tf *transformer) transformGo(file *ast.File) *ast.File {
 		}
 
 		// The object itself is blacklisted, e.g. a type definition.
-		if _, ok := tf.blacklist[obj]; ok {
+		if tf.blacklist[obj] {
 			return true
 		}
 
@@ -1024,7 +1024,7 @@ func (tf *transformer) transformGo(file *ast.File) *ast.File {
 		for {
 			tf.nameCounter++
 			name = encodeIntToName(tf.nameCounter)
-			if _, ok := tf.existingNames[name]; !ok {
+			if !tf.existingNames[name] {
 				break
 			}
 		}
@@ -1038,14 +1038,14 @@ func (tf *transformer) transformGo(file *ast.File) *ast.File {
 	return astutil.Apply(file, pre, nil).(*ast.File)
 }
 
-func blacklistStruct(named *types.Named, blacklist map[types.Object]struct{}) {
-	blacklist[named.Obj()] = struct{}{}
+func blacklistStruct(named *types.Named, blacklist map[types.Object]bool) {
+	blacklist[named.Obj()] = true
 	strct, ok := named.Underlying().(*types.Struct)
 	if !ok {
 		return
 	}
 	for i := 0; i < strct.NumFields(); i++ {
-		blacklist[strct.Field(i)] = struct{}{}
+		blacklist[strct.Field(i)] = true
 	}
 }