diff --git a/examples/advanced/nested-import-global-propagation-default/lib/lib.variant b/examples/advanced/nested-import-global-propagation-default/lib/lib.variant
new file mode 100644
index 0000000..3230b94
--- /dev/null
+++ b/examples/advanced/nested-import-global-propagation-default/lib/lib.variant
@@ -0,0 +1,16 @@
+option "project-dir" {
+  description = "Terraform projects directory"
+  default = "./defaultdir"
+  type = string
+}
+
+job "terraform plan" {
+  parameter "project" {
+    type = string
+  }
+
+  exec {
+    command = "bash"
+    args    = ["-c", "echo ${opt.project-dir}/${param.project}"]
+  }
+}
diff --git a/examples/advanced/nested-import-global-propagation-default/main.variant b/examples/advanced/nested-import-global-propagation-default/main.variant
new file mode 100644
index 0000000..64cafed
--- /dev/null
+++ b/examples/advanced/nested-import-global-propagation-default/main.variant
@@ -0,0 +1,3 @@
+job "nested" {
+  import = "lib"
+}
diff --git a/examples/advanced/nested-import-global-propagation-incompatible-type/lib/lib.variant b/examples/advanced/nested-import-global-propagation-incompatible-type/lib/lib.variant
new file mode 100644
index 0000000..3230b94
--- /dev/null
+++ b/examples/advanced/nested-import-global-propagation-incompatible-type/lib/lib.variant
@@ -0,0 +1,16 @@
+option "project-dir" {
+  description = "Terraform projects directory"
+  default = "./defaultdir"
+  type = string
+}
+
+job "terraform plan" {
+  parameter "project" {
+    type = string
+  }
+
+  exec {
+    command = "bash"
+    args    = ["-c", "echo ${opt.project-dir}/${param.project}"]
+  }
+}
diff --git a/examples/advanced/nested-import-global-propagation-incompatible-type/main.variant b/examples/advanced/nested-import-global-propagation-incompatible-type/main.variant
new file mode 100644
index 0000000..4d51b19
--- /dev/null
+++ b/examples/advanced/nested-import-global-propagation-incompatible-type/main.variant
@@ -0,0 +1,10 @@
+option "project-dir" {
+  # The default works from geodesic shell `projects` folder
+  default = 1
+  description = "Terraform projects directory"
+  type = number
+}
+
+job "nested" {
+  import = "lib"
+}
diff --git a/examples/advanced/nested-import-global-propagation/defaultdir/project b/examples/advanced/nested-import-global-propagation/defaultdir/project
new file mode 100644
index 0000000..3933966
--- /dev/null
+++ b/examples/advanced/nested-import-global-propagation/defaultdir/project
@@ -0,0 +1 @@
+DEFAULT
\ No newline at end of file
diff --git a/examples/advanced/nested-import-global-propagation/lib/lib.variant b/examples/advanced/nested-import-global-propagation/lib/lib.variant
new file mode 100644
index 0000000..3230b94
--- /dev/null
+++ b/examples/advanced/nested-import-global-propagation/lib/lib.variant
@@ -0,0 +1,16 @@
+option "project-dir" {
+  description = "Terraform projects directory"
+  default = "./defaultdir"
+  type = string
+}
+
+job "terraform plan" {
+  parameter "project" {
+    type = string
+  }
+
+  exec {
+    command = "bash"
+    args    = ["-c", "echo ${opt.project-dir}/${param.project}"]
+  }
+}
diff --git a/examples/advanced/nested-import-global-propagation/main.variant b/examples/advanced/nested-import-global-propagation/main.variant
new file mode 100644
index 0000000..e1d97e1
--- /dev/null
+++ b/examples/advanced/nested-import-global-propagation/main.variant
@@ -0,0 +1,10 @@
+option "project-dir" {
+  # The default works from geodesic shell `projects` folder
+  default = "./overridedir"
+  description = "Terraform projects directory"
+  type = string
+}
+
+job "nested" {
+  import = "lib"
+}
diff --git a/examples/advanced/nested-import-global-propagation/overridedir/project b/examples/advanced/nested-import-global-propagation/overridedir/project
new file mode 100644
index 0000000..0ac28cc
--- /dev/null
+++ b/examples/advanced/nested-import-global-propagation/overridedir/project
@@ -0,0 +1 @@
+OVERRIDE
\ No newline at end of file
diff --git a/main.go b/main.go
index 08c23d5..e7122c7 100644
--- a/main.go
+++ b/main.go
@@ -1,5 +1,7 @@
 package variant
 
+import "fmt"
+
 func RunMain(env Env, opts ...Option) error {
 	cmd, path, args := GetPathAndArgsFromEnv(env)
 
@@ -11,7 +13,7 @@ func RunMain(env Env, opts ...Option) error {
 		}
 	}))
 	if err != nil {
-		panic(err)
+		return fmt.Errorf("loading command: %w", err)
 	}
 
 	return m.Run(args, RunOptions{DisableLocking: false})
diff --git a/main_test.go b/main_test.go
index 8191367..7fdc60f 100644
--- a/main_test.go
+++ b/main_test.go
@@ -154,6 +154,27 @@ func TestExamples(t *testing.T) {
 			args:        []string{"variant", "test"},
 			wd:          "./examples/advanced/import-multi",
 		},
+		{
+			subject:     "nested-import-global-propagation",
+			args:        []string{"variant", "run", "nested", "terraform", "plan", "project"},
+			variantName: "",
+			wd:          "./examples/advanced/nested-import-global-propagation",
+			expectOut:   "./overridedir/project\n",
+		},
+		{
+			subject:     "nested-import-global-propagation-default",
+			args:        []string{"variant", "run", "nested", "terraform", "plan", "project"},
+			variantName: "",
+			wd:          "./examples/advanced/nested-import-global-propagation-default",
+			expectOut:   "./defaultdir/project\n",
+		},
+		{
+			subject:     "nested-import-global-propagation-incompatible-type",
+			args:        []string{"variant", "run", "nested", "terraform", "plan", "project"},
+			variantName: "",
+			wd:          "./examples/advanced/nested-import-global-propagation-incompatible-type",
+			expectErr:   "loading command: merging globals: imported job \"\" has incompatible option \"project-dir\": needs type of cty.Number, encountered cty.String",
+		},
 		{
 			subject:     "options",
 			variantName: "",
@@ -292,8 +313,8 @@ func TestExamples(t *testing.T) {
 			if tc.expectErr != "" {
 				if err == nil {
 					t.Fatalf("Expected error didn't occur")
-				} else if err.Error() != tc.expectErr {
-					t.Fatalf("Unexpected error: want %q, got %q\n%s", tc.expectErr, err.Error(), errOut)
+				} else if d := cmp.Diff(tc.expectErr, err.Error()); d != "" {
+					t.Fatalf("Unexpected error:\nDIFF:\n%s\nSTDERR:\n%s", d, errOut)
 				}
 			} else if err != nil {
 				t.Fatalf("%+v\n%s", err, errOut)
diff --git a/pkg/app/load.go b/pkg/app/load.go
index 6b50ffb..e85f928 100644
--- a/pkg/app/load.go
+++ b/pkg/app/load.go
@@ -8,6 +8,8 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/hashicorp/hcl/v2/ext/typeexpr"
+
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/gohcl"
 	"github.com/hashicorp/hcl/v2/hclparse"
@@ -257,6 +259,8 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 
 	var conf *HCL2Config
 
+	var globals []JobSpec
+
 	jobByName := map[string]JobSpec{}
 	for _, j := range jobs {
 		jobByName[j.Name] = j
@@ -288,7 +292,10 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 						//
 						// If the user-side has a global parameter/option that has the same name as the library-side,
 						// their types MUST match.
-						merged := mergeJobs(importedJob, j)
+						merged, err := mergeParamsAndOpts(importedJob, j)
+						if err != nil {
+							return nil, fmt.Errorf("merging globals: %w", err)
+						}
 
 						merged.Name = ""
 
@@ -302,6 +309,9 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 					} else {
 						// Import the top-level job in the library as the non-top-level job on the user side
 						newJobName = j.Name
+
+						// And merge global parameters and options
+						globals = append(globals, importedJob)
 					}
 
 					importedJob.Name = newJobName
@@ -316,12 +326,27 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 		}
 	}
 
+	root := jobByName[""]
+
+	for _, g := range globals {
+		merged, err := mergeParamsAndOpts(g, root)
+		if err != nil {
+			return nil, fmt.Errorf("merging globals: %w", err)
+		}
+
+		root = *merged
+	}
+
+	jobByName[""] = root
+
 	if conf == nil {
 		conf = cc
 	}
 
 	app.Config = conf
 
+	app.Config.JobSpec = root
+
 	app.JobByName = jobByName
 
 	var newJobs []JobSpec
@@ -335,7 +360,7 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 	return app, nil
 }
 
-func mergeJobs(src JobSpec, dst JobSpec) *JobSpec {
+func mergeParamsAndOpts(src JobSpec, dst JobSpec) (*JobSpec, error) {
 	paramMap := map[string]Parameter{}
 	optMap := map[string]OptionSpec{}
 
@@ -348,14 +373,38 @@ func mergeJobs(src JobSpec, dst JobSpec) *JobSpec {
 	}
 
 	for _, p := range src.Parameters {
-		if _, exists := paramMap[p.Name]; !exists {
+		if existing, exists := paramMap[p.Name]; !exists {
 			paramMap[p.Name] = p
+		} else {
+			exTy, err := typeexpr.TypeConstraint(existing.Type)
+			if err != nil {
+				return nil, fmt.Errorf("parsing parameter type: %w", err)
+			}
+			toTy, err := typeexpr.TypeConstraint(p.Type)
+			if err != nil {
+				return nil, fmt.Errorf("parsing parameter type: %w", err)
+			}
+			if exTy != toTy {
+				return nil, fmt.Errorf("imported job %q has incompatible parameter %q: needs type of %v, encountered %v", src.Name, p.Name, exTy.GoString(), toTy.GoString())
+			}
 		}
 	}
 
 	for _, o := range src.Options {
-		if _, exists := optMap[o.Name]; !exists {
+		if existing, exists := optMap[o.Name]; !exists {
 			optMap[o.Name] = o
+		} else {
+			exTy, err := typeexpr.TypeConstraint(existing.Type)
+			if err != nil {
+				return nil, fmt.Errorf("parsing option type: %w", err)
+			}
+			toTy, err := typeexpr.TypeConstraint(o.Type)
+			if err != nil {
+				return nil, fmt.Errorf("parsing option type: %w", err)
+			}
+			if exTy != toTy {
+				return nil, fmt.Errorf("imported job %q has incompatible option %q: needs type of %v, encountered %v", src.Name, o.Name, exTy.GoString(), toTy.GoString())
+			}
 		}
 	}
 
@@ -375,5 +424,5 @@ func mergeJobs(src JobSpec, dst JobSpec) *JobSpec {
 	dst.Parameters = params
 	dst.Options = opts
 
-	return &dst
+	return &dst, nil
 }