diff --git a/go/analysis/unitchecker/unitchecker.go b/go/analysis/unitchecker/unitchecker.go
index 0a40652c1b5..36eed808d87 100644
--- a/go/analysis/unitchecker/unitchecker.go
+++ b/go/analysis/unitchecker/unitchecker.go
@@ -51,6 +51,7 @@ import (
 	"golang.org/x/tools/go/analysis/internal/analysisflags"
 	"golang.org/x/tools/internal/facts"
 	"golang.org/x/tools/internal/typeparams"
+	"golang.org/x/tools/internal/versions"
 )
 
 // A Config describes a compilation unit to be analyzed.
@@ -262,6 +263,7 @@ func run(fset *token.FileSet, cfg *Config, analyzers []*analysis.Analyzer) ([]re
 		Selections: make(map[*ast.SelectorExpr]*types.Selection),
 	}
 	typeparams.InitInstanceInfo(info)
+	versions.InitFileVersions(info)
 
 	pkg, err := tc.Check(cfg.ImportPath, fset, files, info)
 	if err != nil {
diff --git a/go/loader/loader.go b/go/loader/loader.go
index edf62c2cc03..41ee08b9b0a 100644
--- a/go/loader/loader.go
+++ b/go/loader/loader.go
@@ -24,6 +24,7 @@ import (
 	"golang.org/x/tools/go/ast/astutil"
 	"golang.org/x/tools/go/internal/cgo"
 	"golang.org/x/tools/internal/typeparams"
+	"golang.org/x/tools/internal/versions"
 )
 
 var ignoreVendor build.ImportMode
@@ -1040,6 +1041,7 @@ func (imp *importer) newPackageInfo(path, dir string) *PackageInfo {
 		dir:       dir,
 	}
 	typeparams.InitInstanceInfo(&info.Info)
+	versions.InitFileVersions(&info.Info)
 
 	// Copy the types.Config so we can vary it across PackageInfos.
 	tc := imp.conf.TypeChecker
diff --git a/go/packages/packages.go b/go/packages/packages.go
index fd7ecf77e99..bd79efc1aaf 100644
--- a/go/packages/packages.go
+++ b/go/packages/packages.go
@@ -29,6 +29,7 @@ import (
 	"golang.org/x/tools/internal/packagesinternal"
 	"golang.org/x/tools/internal/typeparams"
 	"golang.org/x/tools/internal/typesinternal"
+	"golang.org/x/tools/internal/versions"
 )
 
 // A LoadMode controls the amount of detail to return when loading.
@@ -1018,6 +1019,7 @@ func (ld *loader) loadPackage(lpkg *loaderPackage) {
 		Selections: make(map[*ast.SelectorExpr]*types.Selection),
 	}
 	typeparams.InitInstanceInfo(lpkg.TypesInfo)
+	versions.InitFileVersions(lpkg.TypesInfo)
 	lpkg.TypesSizes = ld.sizes
 
 	importer := importerFunc(func(path string) (*types.Package, error) {
diff --git a/go/ssa/builder.go b/go/ssa/builder.go
index b64c50b4349..b607c29ad4b 100644
--- a/go/ssa/builder.go
+++ b/go/ssa/builder.go
@@ -82,6 +82,7 @@ import (
 	"sync"
 
 	"golang.org/x/tools/internal/typeparams"
+	"golang.org/x/tools/internal/versions"
 )
 
 type opaqueType struct {
@@ -1744,8 +1745,7 @@ func (b *builder) forStmt(fn *Function, s *ast.ForStmt, label *lblock) {
 	// Use forStmtGo122 instead if it applies.
 	if s.Init != nil {
 		if assign, ok := s.Init.(*ast.AssignStmt); ok && assign.Tok == token.DEFINE {
-			major, minor := parseGoVersion(fn.goversion)
-			afterGo122 := major >= 1 && minor >= 22
+			afterGo122 := versions.Compare(fn.goversion, "go1.21") > 0
 			if afterGo122 {
 				b.forStmtGo122(fn, s, label)
 				return
@@ -2195,9 +2195,7 @@ func (b *builder) rangeStmt(fn *Function, s *ast.RangeStmt, label *lblock) {
 		}
 	}
 
-	major, minor := parseGoVersion(fn.goversion)
-	afterGo122 := major >= 1 && minor >= 22
-
+	afterGo122 := versions.Compare(fn.goversion, "go1.21") > 0
 	if s.Tok == token.DEFINE && !afterGo122 {
 		// pre-go1.22: If iteration variables are defined (:=), this
 		// occurs once outside the loop.
diff --git a/go/ssa/create.go b/go/ssa/create.go
index eaaf4695e85..653ce2e5c3d 100644
--- a/go/ssa/create.go
+++ b/go/ssa/create.go
@@ -16,6 +16,7 @@ import (
 	"sync"
 
 	"golang.org/x/tools/internal/typeparams"
+	"golang.org/x/tools/internal/versions"
 )
 
 // NewProgram returns a new SSA Program.
@@ -245,7 +246,7 @@ func (prog *Program) CreatePackage(pkg *types.Package, files []*ast.File, info *
 	if len(files) > 0 {
 		// Go source package.
 		for _, file := range files {
-			goversion := goversionOf(p, file)
+			goversion := versions.Lang(versions.FileVersions(p.info, file))
 			for _, decl := range file.Decls {
 				membersFromDecl(p, decl, goversion)
 			}
diff --git a/go/ssa/interp/interp_test.go b/go/ssa/interp/interp_test.go
index 7e12dd84131..d217ded0783 100644
--- a/go/ssa/interp/interp_test.go
+++ b/go/ssa/interp/interp_test.go
@@ -37,6 +37,7 @@ import (
 	"golang.org/x/tools/go/ssa"
 	"golang.org/x/tools/go/ssa/interp"
 	"golang.org/x/tools/go/ssa/ssautil"
+	"golang.org/x/tools/internal/testenv"
 	"golang.org/x/tools/internal/typeparams"
 )
 
@@ -172,7 +173,12 @@ func run(t *testing.T, input string, goroot string) {
 		t.Skipf("skipping: width32.go checks behavior for a 32-bit int")
 	}
 
-	conf := loader.Config{Build: &ctx}
+	gover := ""
+	if p := testenv.Go1Point(); p > 0 {
+		gover = fmt.Sprintf("go1.%d", p)
+	}
+
+	conf := loader.Config{Build: &ctx, TypeChecker: types.Config{GoVersion: gover}}
 	if _, err := conf.FromArgs([]string{input}, true); err != nil {
 		t.Fatalf("FromArgs(%s) failed: %s", input, err)
 	}
diff --git a/go/ssa/source.go b/go/ssa/source.go
index 7b1eb8527f9..6700305bd9a 100644
--- a/go/ssa/source.go
+++ b/go/ssa/source.go
@@ -11,7 +11,6 @@ package ssa
 // the originating syntax, as specified.
 
 import (
-	"fmt"
 	"go/ast"
 	"go/token"
 	"go/types"
@@ -132,31 +131,6 @@ func findNamedFunc(pkg *Package, pos token.Pos) *Function {
 	return nil
 }
 
-// goversionOf returns the goversion of a node in the package
-// where the node is either a function declaration or the initial
-// value of a package level variable declaration.
-func goversionOf(p *Package, file *ast.File) string {
-	if p.info == nil {
-		return ""
-	}
-
-	// TODO(taking): Update to the following when internal/versions available:
-	//	return versions.Lang(versions.FileVersions(p.info, file))
-	return fileVersions(file)
-}
-
-// TODO(taking): Remove when internal/versions is available.
-var fileVersions = func(file *ast.File) string { return "" }
-
-// parses a goXX.YY version or returns a negative version on an error.
-// TODO(taking): Switch to a permanent solution when internal/versions is submitted.
-func parseGoVersion(x string) (major, minor int) {
-	if _, err := fmt.Sscanf(x, "go%d.%d", &major, &minor); err != nil || major < 0 || minor < 0 {
-		return -1, -1
-	}
-	return
-}
-
 // ValueForExpr returns the SSA Value that corresponds to non-constant
 // expression e.
 //
diff --git a/go/ssa/ssautil/load.go b/go/ssa/ssautil/load.go
index 67e75cb261a..fb62c2bd413 100644
--- a/go/ssa/ssautil/load.go
+++ b/go/ssa/ssautil/load.go
@@ -15,6 +15,7 @@ import (
 	"golang.org/x/tools/go/packages"
 	"golang.org/x/tools/go/ssa"
 	"golang.org/x/tools/internal/typeparams"
+	"golang.org/x/tools/internal/versions"
 )
 
 // Packages creates an SSA program for a set of packages.
@@ -165,7 +166,7 @@ func BuildPackage(tc *types.Config, fset *token.FileSet, pkg *types.Package, fil
 		Selections: make(map[*ast.SelectorExpr]*types.Selection),
 	}
 	typeparams.InitInstanceInfo(info)
-	// versions.InitFileVersions(info) // TODO(taking): Enable when internal/versions is available.
+	versions.InitFileVersions(info)
 	if err := types.NewChecker(tc, fset, pkg, info).Files(files); err != nil {
 		return nil, nil, err
 	}
diff --git a/go/ssa/versions_go122.go b/go/ssa/versions_go122.go
deleted file mode 100644
index b74165a8e32..00000000000
--- a/go/ssa/versions_go122.go
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2023 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.22
-// +build go1.22
-
-package ssa
-
-import (
-	"go/ast"
-)
-
-func init() {
-	fileVersions = func(file *ast.File) string {
-		if maj, min := parseGoVersion(file.GoVersion); maj >= 0 && min >= 0 {
-			return file.GoVersion
-		}
-		return ""
-	}
-}
diff --git a/go/types/typeutil/callee_test.go b/go/types/typeutil/callee_test.go
index 345236147d8..ed590719b59 100644
--- a/go/types/typeutil/callee_test.go
+++ b/go/types/typeutil/callee_test.go
@@ -15,6 +15,7 @@ import (
 
 	"golang.org/x/tools/go/types/typeutil"
 	"golang.org/x/tools/internal/typeparams"
+	"golang.org/x/tools/internal/versions"
 )
 
 func TestStaticCallee(t *testing.T) {
@@ -129,6 +130,7 @@ func testStaticCallee(t *testing.T, contents []string) {
 		Selections: make(map[*ast.SelectorExpr]*types.Selection),
 	}
 	typeparams.InitInstanceInfo(info)
+	versions.InitFileVersions(info)
 
 	var files []*ast.File
 	for i, content := range contents {
diff --git a/refactor/satisfy/find_test.go b/refactor/satisfy/find_test.go
index 2cbd8c15ca3..995b95f168d 100644
--- a/refactor/satisfy/find_test.go
+++ b/refactor/satisfy/find_test.go
@@ -16,6 +16,7 @@ import (
 	"testing"
 
 	"golang.org/x/tools/internal/typeparams"
+	"golang.org/x/tools/internal/versions"
 	"golang.org/x/tools/refactor/satisfy"
 )
 
@@ -228,6 +229,7 @@ func constraints(t *testing.T, src string) []string {
 		Selections: make(map[*ast.SelectorExpr]*types.Selection),
 	}
 	typeparams.InitInstanceInfo(info)
+	versions.InitFileVersions(info)
 	conf := types.Config{
 		Importer: importer.Default(),
 	}