diff --git a/command/registry.go b/command/registry.go
index b197303fd..960049197 100644
--- a/command/registry.go
+++ b/command/registry.go
@@ -47,6 +47,10 @@ func TrySetupHCP(cfg packer.Handler) hcl.Diagnostics {
 func setupRegistryForPackerConfig(pc *hcl2template.PackerConfig) hcl.Diagnostics {
 	var diags hcl.Diagnostics
 
+	if env.IsHCPDisabled() {
+		return nil
+	}
+
 	hasHCP := false
 
 	for _, build := range pc.Builds {
@@ -55,6 +59,14 @@ func setupRegistryForPackerConfig(pc *hcl2template.PackerConfig) hcl.Diagnostics
 		}
 	}
 
+	if env.HasPackerRegistryBucket() {
+		hasHCP = true
+	}
+
+	if !hasHCP {
+		return nil
+	}
+
 	if hasHCP && len(pc.Builds) > 1 {
 		diags = append(diags, &hcl.Diagnostic{
 			Severity: hcl.DiagError,
@@ -67,14 +79,6 @@ func setupRegistryForPackerConfig(pc *hcl2template.PackerConfig) hcl.Diagnostics
 		return diags
 	}
 
-	if env.IsPAREnabled() {
-		hasHCP = true
-	}
-
-	if !hasHCP {
-		return diags
-	}
-
 	var err error
 	pc.Bucket, err = registry.NewBucketWithIteration(registry.IterationOptions{
 		TemplateBaseDir: pc.Basedir,
@@ -111,6 +115,14 @@ func setupRegistryForPackerConfig(pc *hcl2template.PackerConfig) hcl.Diagnostics
 		}
 	}
 
+	if pc.Bucket.Slug == "" {
+		return append(diags, &hcl.Diagnostic{
+			Summary:  "bucket name cannot be empty",
+			Detail:   "empty bucket name, please set it with the HCP_PACKER_BUCKET_NAME environment variable, or in a `hcp_packer_registry` block",
+			Severity: hcl.DiagError,
+		})
+	}
+
 	vals, diags := pc.Datasources.Values()
 	if diags != nil {
 		return diags
@@ -254,7 +266,11 @@ func iterValueToDSOutput(iterVal map[string]cty.Value) iterds.DatasourceOutput {
 }
 
 func setupRegistryForPackerCore(cfg *CoreWrapper) hcl.Diagnostics {
-	if !env.IsPAREnabled() {
+	if env.IsHCPDisabled() {
+		return nil
+	}
+
+	if !env.HasPackerRegistryBucket() {
 		return nil
 	}
 
@@ -276,6 +292,14 @@ func setupRegistryForPackerCore(cfg *CoreWrapper) hcl.Diagnostics {
 	}
 	core.Bucket.LoadDefaultSettingsFromEnv()
 
+	if core.Bucket.Slug == "" {
+		return append(diags, &hcl.Diagnostic{
+			Summary:  "bucket name cannot be empty",
+			Detail:   "empty bucket name, please set it with the HCP_PACKER_BUCKET_NAME environment variable",
+			Severity: hcl.DiagError,
+		})
+	}
+
 	for _, b := range core.Template.Builders {
 		// Get all builds slated within config ignoring any only or exclude flags.
 		core.Bucket.RegisterBuildForComponent(b.Name)
diff --git a/internal/registry/env/env.go b/internal/registry/env/env.go
index 9f8f49612..beb9397ef 100644
--- a/internal/registry/env/env.go
+++ b/internal/registry/env/env.go
@@ -6,18 +6,23 @@ import (
 )
 
 func HasClientID() bool {
-	_, ok := os.LookupEnv(HCPClientID)
-	return ok
+	return hasEnvVar(HCPClientID)
 }
 
 func HasClientSecret() bool {
-	_, ok := os.LookupEnv(HCPClientSecret)
-	return ok
+	return hasEnvVar(HCPClientSecret)
 }
 
 func HasPackerRegistryBucket() bool {
-	_, ok := os.LookupEnv(HCPPackerBucket)
-	return ok
+	return hasEnvVar(HCPPackerBucket)
+}
+
+func hasEnvVar(varName string) bool {
+	val, ok := os.LookupEnv(varName)
+	if !ok {
+		return false
+	}
+	return val != ""
 }
 
 func HasHCPCredentials() bool {
@@ -35,7 +40,7 @@ func HasHCPCredentials() bool {
 	return true
 }
 
-func IsPAREnabled() bool {
-	val, ok := os.LookupEnv(HCPPackerRegistry)
-	return ok && strings.ToLower(val) != "off" && val != "0"
+func IsHCPDisabled() bool {
+	hcp, ok := os.LookupEnv(HCPPackerRegistry)
+	return ok && strings.ToLower(hcp) == "off" || hcp == "0"
 }
diff --git a/internal/registry/env/env_test.go b/internal/registry/env/env_test.go
index 5d3a9afa4..c2fd27598 100644
--- a/internal/registry/env/env_test.go
+++ b/internal/registry/env/env_test.go
@@ -1,50 +1,46 @@
 package env
 
 import (
-	"os"
 	"testing"
 )
 
-func Test_IsPAREnabled(t *testing.T) {
+func Test_IsHCPDisabled(t *testing.T) {
 	tcs := []struct {
-		name   string
-		value  string
-		output bool
+		name           string
+		registry_value string
+		output         bool
 	}{
 		{
-			name:   "set with 1",
-			value:  "1",
-			output: true,
+			name:           "nothing set",
+			registry_value: "",
+			output:         false,
 		},
 		{
-			name:   "set with ON",
-			value:  "ON",
-			output: true,
+			name:           "registry set with 1",
+			registry_value: "1",
+			output:         false,
 		},
 		{
-			name:   "set with 0",
-			value:  "0",
-			output: false,
+			name:           "registry set with 0",
+			registry_value: "0",
+			output:         true,
 		},
 		{
-			name:   "set with OFF",
-			value:  "OFF",
-			output: false,
+			name:           "registry set with OFF",
+			registry_value: "OFF",
+			output:         true,
 		},
 		{
-			name:   "unset",
-			value:  "",
-			output: false,
+			name:           "registry set with off",
+			registry_value: "off",
+			output:         true,
 		},
 	}
 
 	for _, tc := range tcs {
 		t.Run(tc.name, func(t *testing.T) {
-			if tc.value != "" {
-				_ = os.Setenv(HCPPackerRegistry, tc.value)
-				defer os.Unsetenv(HCPPackerRegistry)
-			}
-			out := IsPAREnabled()
+			t.Setenv(HCPPackerRegistry, tc.registry_value)
+			out := IsHCPDisabled()
 			if out != tc.output {
 				t.Fatalf("unexpected output: %t", out)
 			}