diff --git a/nix/nix.go b/nix/nix.go
index 0e37730ef89..246cf11c8c5 100644
--- a/nix/nix.go
+++ b/nix/nix.go
@@ -179,8 +179,10 @@ const (
 //
 // The semantic component is sourced from <https://semver.org/#is-there-a-suggested-regular-expression-regex-to-check-a-semver-string>.
 // It's been modified to tolerate Nix prerelease versions, which don't have a
-// hyphen before the prerelease component and contain underscores.
-var versionRegexp = regexp.MustCompile(`^(.+) \(.+\) ((?P<major>0|[1-9]\d*)\.(?P<minor>0|[1-9]\d*)\.(?P<patch>0|[1-9]\d*)(?:(?:-|pre)(?P<prerelease>(?:0|[1-9]\d*|\d*[_a-zA-Z-][_0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[_a-zA-Z-][_0-9a-zA-Z-]*))*))?(?:\+(?P<buildmetadata>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?)$`)
+// hyphen before the prerelease component and contain underscores. The patch
+// component is optional because newer Nix releases drop it (e.g. "2.33" or
+// "2.33pre20251107_479b6b73").
+var versionRegexp = regexp.MustCompile(`^(.+) \(.+\) ((?P<major>0|[1-9]\d*)\.(?P<minor>0|[1-9]\d*)(?:\.(?P<patch>0|[1-9]\d*))?(?:(?:-|pre)(?P<prerelease>(?:0|[1-9]\d*|\d*[_a-zA-Z-][_0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[_a-zA-Z-][_0-9a-zA-Z-]*))*))?(?:\+(?P<buildmetadata>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?)$`)
 
 // preReleaseRegexp matches Nix prerelease version strings, which are not valid
 // semvers.
@@ -295,15 +297,47 @@ func (i Info) AtLeast(version string) bool {
 	if !semver.IsValid(version) {
 		panic(fmt.Sprintf("nix.atLeast: invalid version %q", version[1:]))
 	}
+	current := i.semver()
+	if !semver.IsValid(current) {
+		return false
+	}
+	return semver.Compare(current, version) >= 0
+}
+
+// semver converts i.Version into a valid semantic version string with a
+// leading "v" so it can be compared with the semver package. It returns an
+// empty string when i.Version is empty or cannot be coerced.
+//
+// Nix prerelease versions (e.g. "2.23.0pre20240526_7de033d6") aren't valid
+// semvers, and newer Nix releases drop the patch component entirely (e.g.
+// "2.33" or "2.33pre20251107_479b6b73"). This coerces both forms into a valid
+// semver, e.g. "v2.33.0-pre.20251107+479b6b73".
+func (i Info) semver() string {
+	if i.Version == "" {
+		return ""
+	}
 	if semver.IsValid("v" + i.Version) {
-		return semver.Compare("v"+i.Version, version) >= 0
+		return "v" + i.Version
 	}
 
-	// If the version isn't a valid semver, check to see if it's a
-	// prerelease (e.g., 2.23.0pre20240526_7de033d6) and coerce it to a
-	// valid version (2.23.0-pre.20240526+7de033d6) so we can compare it.
-	prerelease := preReleaseRegexp.ReplaceAllString(i.Version, "-pre.$date+$commit")
-	return semver.Compare("v"+prerelease, version) >= 0
+	// Coerce a Nix prerelease suffix (e.g. "pre20240526_7de033d6") into a
+	// semver prerelease+build component (e.g. "-pre.20240526+7de033d6").
+	v := preReleaseRegexp.ReplaceAllString(i.Version, "-pre.$date+$commit")
+
+	// semver requires a major.minor.patch base for prerelease versions, but
+	// newer Nix releases omit the patch. Insert ".0" when it's missing.
+	base, suffix := v, ""
+	if idx := strings.IndexAny(v, "-+"); idx >= 0 {
+		base, suffix = v[:idx], v[idx:]
+	}
+	if strings.Count(base, ".") == 1 {
+		base += ".0"
+	}
+	coerced := "v" + base + suffix
+	if !semver.IsValid(coerced) {
+		return ""
+	}
+	return coerced
 }
 
 // sourceProfileMutex guards against multiple goroutines attempting to source
diff --git a/nix/nix_test.go b/nix/nix_test.go
index 1604edf39a6..a9ca2458260 100644
--- a/nix/nix_test.go
+++ b/nix/nix_test.go
@@ -112,6 +112,10 @@ func TestParseVersionInfoShort(t *testing.T) {
 		{"nix (Nix) 2.23.0pre20240526_7de033d6", "nix", "2.23.0pre20240526_7de033d6"},
 		{"command (Nix) name (Nix) 2.21.2", "command (Nix) name", "2.21.2"},
 		{"nix (Lix, like Nix) 2.90.0-beta.1", "nix", "2.90.0-beta.1"},
+		// https://github.com/jetify-com/devbox/issues/2766
+		// Newer Nix releases drop the patch component.
+		{"nix (Nix) 2.33", "nix", "2.33"},
+		{"nix (Nix) 2.33pre20251107_479b6b73", "nix", "2.33pre20251107_479b6b73"},
 	}
 
 	for _, tt := range cases {
@@ -186,6 +190,27 @@ func TestVersionInfoAtLeast(t *testing.T) {
 		t.Errorf("got %s < %s", info.Version, "2.23.0-pre.1")
 	}
 
+	// https://github.com/jetify-com/devbox/issues/2766
+	// Newer Nix releases drop the patch component, including in prereleases.
+	info.Version = "2.33"
+	if !info.AtLeast(Version2_18) {
+		t.Errorf("got %s < %s", info.Version, Version2_18)
+	}
+	if info.AtLeast("2.34.0") {
+		t.Errorf("got %s >= %s", info.Version, "2.34.0")
+	}
+
+	info.Version = "2.33pre20251107_479b6b73"
+	if !info.AtLeast(Version2_18) {
+		t.Errorf("got %s < %s", info.Version, Version2_18)
+	}
+	if !info.AtLeast(MinVersion) {
+		t.Errorf("got %s < %s (MinVersion)", info.Version, MinVersion)
+	}
+	if info.AtLeast("2.33.0") {
+		t.Errorf("got %s >= %s", info.Version, "2.33.0")
+	}
+
 	t.Run("ArgEmptyPanic", func(t *testing.T) {
 		defer func() {
 			if r := recover(); r == nil {