diff --git a/bootstrap/bpdoc/properties.go b/bootstrap/bpdoc/properties.go
index 31b93b1..29e6c56 100644
--- a/bootstrap/bpdoc/properties.go
+++ b/bootstrap/bpdoc/properties.go
@@ -20,6 +20,7 @@ import (
 	"go/doc"
 	"html/template"
 	"reflect"
+	"slices"
 	"strconv"
 	"strings"
 	"unicode"
@@ -34,7 +35,7 @@ import (
 
 func (ps *PropertyStruct) Clone() *PropertyStruct {
 	ret := *ps
-	ret.Properties = append([]Property(nil), ret.Properties...)
+	ret.Properties = slices.Clone(ret.Properties)
 	for i, prop := range ret.Properties {
 		ret.Properties[i] = prop.Clone()
 	}
@@ -44,7 +45,7 @@ func (ps *PropertyStruct) Clone() *PropertyStruct {
 
 func (p *Property) Clone() Property {
 	ret := *p
-	ret.Properties = append([]Property(nil), ret.Properties...)
+	ret.Properties = slices.Clone(ret.Properties)
 	for i, prop := range ret.Properties {
 		ret.Properties[i] = prop.Clone()
 	}
diff --git a/context.go b/context.go
index 6ec1641..a64250d 100644
--- a/context.go
+++ b/context.go
@@ -24,6 +24,7 @@ import (
 	"hash/fnv"
 	"io"
 	"io/ioutil"
+	"maps"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -418,15 +419,7 @@ type Variation struct {
 type variationMap map[string]string
 
 func (vm variationMap) clone() variationMap {
-	if vm == nil {
-		return nil
-	}
-	newVm := make(variationMap)
-	for k, v := range vm {
-		newVm[k] = v
-	}
-
-	return newVm
+	return maps.Clone(vm)
 }
 
 // Compare this variationMap to another one.  Returns true if the every entry in this map
@@ -441,10 +434,7 @@ func (vm variationMap) subsetOf(other variationMap) bool {
 }
 
 func (vm variationMap) equal(other variationMap) bool {
-	if len(vm) != len(other) {
-		return false
-	}
-	return vm.subsetOf(other)
+	return maps.Equal(vm, other)
 }
 
 type singletonInfo struct {
@@ -800,15 +790,10 @@ type transitionMutatorImpl struct {
 
 // Adds each argument in items to l if it's not already there.
 func addToStringListIfNotPresent(l []string, items ...string) []string {
-OUTER:
 	for _, i := range items {
-		for _, existing := range l {
-			if existing == i {
-				continue OUTER
-			}
+		if !slices.Contains(l, i) {
+			l = append(l, i)
 		}
-
-		l = append(l, i)
 	}
 
 	return l
@@ -1746,14 +1731,14 @@ func (c *Context) createVariations(origModule *moduleInfo, mutatorName string,
 
 		m := *origModule
 		newModule := &m
-		newModule.directDeps = append([]depInfo(nil), origModule.directDeps...)
+		newModule.directDeps = slices.Clone(origModule.directDeps)
 		newModule.reverseDeps = nil
 		newModule.forwardDeps = nil
 		newModule.logicModule = newLogicModule
 		newModule.variant = newVariant(origModule, mutatorName, variationName, local)
 		newModule.properties = newProperties
-		newModule.providers = append([]interface{}(nil), origModule.providers...)
-		newModule.providerInitialValueHashes = append([]uint64(nil), origModule.providerInitialValueHashes...)
+		newModule.providers = slices.Clone(origModule.providers)
+		newModule.providerInitialValueHashes = slices.Clone(origModule.providerInitialValueHashes)
 
 		newModules = append(newModules, newModule)
 
diff --git a/glob.go b/glob.go
index 91ae723..8d0748a 100644
--- a/glob.go
+++ b/glob.go
@@ -16,6 +16,7 @@ package blueprint
 
 import (
 	"fmt"
+	"slices"
 	"sort"
 	"strings"
 
@@ -40,7 +41,7 @@ func verifyGlob(key globKey, pattern string, excludes []string, g pathtools.Glob
 func (c *Context) glob(pattern string, excludes []string) ([]string, error) {
 	// Sort excludes so that two globs with the same excludes in a different order reuse the same
 	// key.  Make a copy first to avoid modifying the caller's version.
-	excludes = append([]string(nil), excludes...)
+	excludes = slices.Clone(excludes)
 	sort.Strings(excludes)
 
 	key := globToKey(pattern, excludes)
@@ -54,7 +55,7 @@ func (c *Context) glob(pattern string, excludes []string) ([]string, error) {
 		// Glob has already been done, double check it is identical
 		verifyGlob(key, pattern, excludes, g)
 		// Return a copy so that modifications don't affect the cached value.
-		return append([]string(nil), g.Matches...), nil
+		return slices.Clone(g.Matches), nil
 	}
 
 	// Get a globbed file list
@@ -74,11 +75,11 @@ func (c *Context) glob(pattern string, excludes []string) ([]string, error) {
 		// Getting the list raced with another goroutine, throw away the results and use theirs
 		verifyGlob(key, pattern, excludes, g)
 		// Return a copy so that modifications don't affect the cached value.
-		return append([]string(nil), g.Matches...), nil
+		return slices.Clone(g.Matches), nil
 	}
 
 	// Return a copy so that modifications don't affect the cached value.
-	return append([]string(nil), result.Matches...), nil
+	return slices.Clone(result.Matches), nil
 }
 
 func (c *Context) Globs() pathtools.MultipleGlobResults {
diff --git a/ninja_strings_test.go b/ninja_strings_test.go
index 50a80fa..2789b7a 100644
--- a/ninja_strings_test.go
+++ b/ninja_strings_test.go
@@ -16,6 +16,7 @@ package blueprint
 
 import (
 	"reflect"
+	"slices"
 	"strconv"
 	"strings"
 	"testing"
@@ -271,7 +272,7 @@ func Test_parseNinjaOrSimpleStrings(t *testing.T) {
 
 	for _, tt := range testCases {
 		t.Run(tt.name, func(t *testing.T) {
-			inCopy := append([]string(nil), tt.in...)
+			inCopy := slices.Clone(tt.in)
 
 			scope := newLocalScope(nil, "")
 			scope.AddLocalVariable("abc", "abc")
diff --git a/pathtools/fs_test.go b/pathtools/fs_test.go
index 3b4d4d0..8826c7c 100644
--- a/pathtools/fs_test.go
+++ b/pathtools/fs_test.go
@@ -18,6 +18,7 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
+	"slices"
 	"syscall"
 	"testing"
 )
@@ -233,7 +234,7 @@ func TestFs_ListDirsRecursiveFollowSymlinks(t *testing.T) {
 			t.Run(test.name, func(t *testing.T) {
 				got, err := fs.ListDirsRecursive(filepath.Join(dir, test.name), FollowSymlinks)
 				checkErr(t, test.err, err)
-				want := append([]string(nil), test.dirs...)
+				want := slices.Clone(test.dirs)
 				for i := range want {
 					want[i] = filepath.Join(dir, want[i])
 				}
@@ -279,7 +280,7 @@ func TestFs_ListDirsRecursiveDontFollowSymlinks(t *testing.T) {
 			t.Run(test.name, func(t *testing.T) {
 				got, err := fs.ListDirsRecursive(filepath.Join(dir, test.name), DontFollowSymlinks)
 				checkErr(t, test.err, err)
-				want := append([]string(nil), test.dirs...)
+				want := slices.Clone(test.dirs)
 				for i := range want {
 					want[i] = filepath.Join(dir, want[i])
 				}
diff --git a/proptools/escape.go b/proptools/escape.go
index 9792444..8fcf82e 100644
--- a/proptools/escape.go
+++ b/proptools/escape.go
@@ -15,6 +15,7 @@
 package proptools
 
 import (
+	"slices"
 	"strings"
 	"unsafe"
 )
@@ -33,7 +34,7 @@ func NinjaEscapeList(slice []string) []string {
 			if !sliceCopied {
 				// If this was the first string that was modified by escaping then make a copy of the
 				// input slice to use as the output slice.
-				slice = append([]string(nil), slice...)
+				slice = slices.Clone(slice)
 				sliceCopied = true
 			}
 			slice[i] = escaped
@@ -66,7 +67,7 @@ func ShellEscapeList(slice []string) []string {
 			if !sliceCopied {
 				// If this was the first string that was modified by escaping then make a copy of the
 				// input slice to use as the output slice.
-				slice = append([]string(nil), slice...)
+				slice = slices.Clone(slice)
 				sliceCopied = true
 			}
 			slice[i] = escaped
@@ -83,7 +84,7 @@ func ShellEscapeListIncludingSpaces(slice []string) []string {
 			if !sliceCopied {
 				// If this was the first string that was modified by escaping then make a copy of the
 				// input slice to use as the output slice.
-				slice = append([]string(nil), slice...)
+				slice = slices.Clone(slice)
 				sliceCopied = true
 			}
 			slice[i] = escaped
diff --git a/proptools/escape_test.go b/proptools/escape_test.go
index 2937058..91c9e76 100644
--- a/proptools/escape_test.go
+++ b/proptools/escape_test.go
@@ -18,6 +18,7 @@ import (
 	"bytes"
 	"os/exec"
 	"reflect"
+	"slices"
 	"testing"
 	"unsafe"
 )
@@ -235,7 +236,7 @@ func TestNinjaEscapeList(t *testing.T) {
 		t.Run(tf.name, func(t *testing.T) {
 			for _, tt := range testCases {
 				t.Run(tt.name, func(t *testing.T) {
-					inCopy := append([]string(nil), tt.in...)
+					inCopy := slices.Clone(tt.in)
 
 					got := tf.f(tt.in)
 
diff --git a/proptools/extend.go b/proptools/extend.go
index eec5d43..af4e185 100644
--- a/proptools/extend.go
+++ b/proptools/extend.go
@@ -17,6 +17,7 @@ package proptools
 import (
 	"fmt"
 	"reflect"
+	"slices"
 	"strings"
 )
 
@@ -317,7 +318,7 @@ func extendPropertiesRecursive(dstValues []reflect.Value, srcValue reflect.Value
 						// of destinations to consider.  Make a copy of dstValues if necessary
 						// to avoid modifying the backing array of an input parameter.
 						if !dstValuesCopied {
-							dstValues = append([]reflect.Value(nil), dstValues...)
+							dstValues = slices.Clone(dstValues)
 							dstValuesCopied = true
 						}
 						dstValues = append(dstValues, embeddedDstValue)