diff --git a/cmd/flux/bootstrap.go b/cmd/flux/bootstrap.go
index d48ed437..c87ccf43 100644
--- a/cmd/flux/bootstrap.go
+++ b/cmd/flux/bootstrap.go
@@ -132,6 +132,13 @@ func generateInstallManifests(targetPath, namespace, tmpDir string, localManifes
 			return "", err
 		}
 		bootstrapArgs.version = version
+	} else {
+		if ok, err := install.ExistingVersion(bootstrapArgs.version); err != nil || !ok {
+			if err == nil {
+				err = fmt.Errorf("targeted version '%s' does not exist", bootstrapArgs.version)
+			}
+			return "", err
+		}
 	}
 
 	opts := install.Options{
diff --git a/cmd/flux/install.go b/cmd/flux/install.go
index 8bd02327..7816023f 100644
--- a/cmd/flux/install.go
+++ b/cmd/flux/install.go
@@ -106,19 +106,9 @@ func installCmdRun(cmd *cobra.Command, args []string) error {
 	ctx, cancel := context.WithTimeout(context.Background(), rootArgs.timeout)
 	defer cancel()
 
-	tmpDir, err := ioutil.TempDir("", rootArgs.namespace)
-	if err != nil {
-		return err
-	}
-	defer os.RemoveAll(tmpDir)
-
-	if !installExport {
-		logger.Generatef("generating manifests")
-	}
-
 	components := append(installDefaultComponents, installExtraComponents...)
-
-	if err := utils.ValidateComponents(components); err != nil {
+	err := utils.ValidateComponents(components)
+	if err != nil {
 		return err
 	}
 
@@ -127,6 +117,23 @@ func installCmdRun(cmd *cobra.Command, args []string) error {
 		if err != nil {
 			return err
 		}
+	} else {
+		if ok, err := install.ExistingVersion(installVersion); err != nil || !ok {
+			if err == nil {
+				err = fmt.Errorf("targeted version '%s' does not exist", installVersion)
+			}
+			return err
+		}
+	}
+
+	tmpDir, err := ioutil.TempDir("", rootArgs.namespace)
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(tmpDir)
+
+	if !installExport {
+		logger.Generatef("generating manifests")
 	}
 
 	opts := install.Options{
diff --git a/pkg/manifestgen/install/install.go b/pkg/manifestgen/install/install.go
index feb83046..f5168545 100644
--- a/pkg/manifestgen/install/install.go
+++ b/pkg/manifestgen/install/install.go
@@ -87,7 +87,7 @@ func GetLatestVersion() (string, error) {
 
 	res, err := c.Get(ghURL)
 	if err != nil {
-		return "", fmt.Errorf("calling GitHub API failed: %w", err)
+		return "", fmt.Errorf("GitHub API call failed: %w", err)
 	}
 
 	if res.Body != nil {
@@ -104,3 +104,32 @@ func GetLatestVersion() (string, error) {
 
 	return m.Tag, err
 }
+
+// ExistingVersion calls the GitHub API to confirm the given version does exist.
+func ExistingVersion(version string) (bool, error) {
+	if !strings.HasPrefix(version, "v") {
+		version = "v" + version
+	}
+
+	ghURL := fmt.Sprintf("https://api.github.com/repos/fluxcd/flux2/releases/tags/%s", version)
+	c := http.DefaultClient
+	c.Timeout = 15 * time.Second
+
+	res, err := c.Get(ghURL)
+	if err != nil {
+		return false, fmt.Errorf("GitHub API call failed: %w", err)
+	}
+
+	if res.Body != nil {
+		defer res.Body.Close()
+	}
+
+	switch res.StatusCode {
+	case http.StatusOK:
+		return true, nil
+	case http.StatusNotFound:
+		return false, nil
+	default:
+		return false, fmt.Errorf("GitHub API returned an unexpected status code (%d)", res.StatusCode)
+	}
+}