src/cmd/go/internal/gover/mod.go                 |  3 +++
 src/cmd/go/testdata/script/mod_get_toolchain.txt | 10 ++++++----

diff --git a/src/cmd/go/internal/gover/mod.go b/src/cmd/go/internal/gover/mod.go
index d3cc17068def6d19cc51f4a25a2a61b1bbd543a9..3ac5ae8824b2337e219060720034499cc3056c8f 100644
--- a/src/cmd/go/internal/gover/mod.go
+++ b/src/cmd/go/internal/gover/mod.go
@@ -109,6 +109,9 @@ // ModIsPrerelease reports whether v is a prerelease version for the module with the given path.
 // The caller is assumed to have checked that ModIsValid(path, vers) is true.
 func ModIsPrerelease(path, vers string) bool {
 	if IsToolchain(path) {
+		if path == "toolchain" {
+			return IsPrerelease(FromToolchain(vers))
+		}
 		return IsPrerelease(vers)
 	}
 	return semver.Prerelease(vers) != ""
diff --git a/src/cmd/go/testdata/script/mod_get_toolchain.txt b/src/cmd/go/testdata/script/mod_get_toolchain.txt
index 758142d668f9c6bbf90f14c685fff633eff91f4c..901a0bb819667f5983755d22b426fbcd64f15f18 100644
--- a/src/cmd/go/testdata/script/mod_get_toolchain.txt
+++ b/src/cmd/go/testdata/script/mod_get_toolchain.txt
@@ -89,12 +89,14 @@ stderr '^go: added toolchain go1.24rc1$'
 grep 'go 1.22.9' go.mod  # no longer implied
 grep 'toolchain go1.24rc1' go.mod
 
-# go get toolchain@latest finds go1.999testmod.
+# go get toolchain@latest finds go1.23.9.
 cp go.mod.orig go.mod
 go get toolchain@latest
-stderr '^go: added toolchain go1.999testmod$'
+stderr '^go: added toolchain go1.23.9$'
 grep 'go 1.21' go.mod
-grep 'toolchain go1.999testmod' go.mod
+grep 'toolchain go1.23.9' go.mod
+
+
 
 # Bug fixes.
 
@@ -110,7 +112,7 @@ stderr '^go: upgraded go 1.19 => 1.21.0'
 
 # go get toolchain@1.24rc1 is OK too.
 go get toolchain@1.24rc1
-stderr '^go: downgraded toolchain go1.999testmod => go1.24rc1$'
+stderr '^go: downgraded toolchain go1.99rc1 => go1.24rc1$'
 
 # go get go@1.21 should work if we are the Go 1.21 language version,
 # even though there's no toolchain for it.