diff --git a/internal/builder/config.go b/internal/builder/config.go
index fa253e8..a0f547f 100644
--- a/internal/builder/config.go
+++ b/internal/builder/config.go
@@ -64,7 +64,6 @@ type Module struct {
 	Import string `mapstructure:"import"` // if not specified, this is the path part of the go mods
 	GoMod  string `mapstructure:"gomod"`  // a gomod-compatible spec for the module
 	Path   string `mapstructure:"path"`   // an optional path to the local version of this module
-	Core   bool   `mapstructure:"core"`   // whether this module comes from core, meaning that no further dependencies will be added
 }
 
 // DefaultConfig creates a new config, with default values
@@ -134,7 +133,7 @@ func (c *Config) ParseModules() error {
 func parseModules(mods []Module) ([]Module, error) {
 	var parsedModules []Module
 	for _, mod := range mods {
-		if mod.GoMod == "" && !mod.Core {
+		if mod.GoMod == "" {
 			return mods, fmt.Errorf("%w, module: %q", ErrInvalidGoMod, mod.GoMod)
 		}
 
diff --git a/internal/builder/config_test.go b/internal/builder/config_test.go
index 08fab22..59e99cb 100644
--- a/internal/builder/config_test.go
+++ b/internal/builder/config_test.go
@@ -65,9 +65,9 @@ func TestRelativePath(t *testing.T) {
 func TestModuleFromCore(t *testing.T) {
 	// prepare
 	cfg := Config{
-		Extensions: []Module{{
-			Core:   true,
+		Extensions: []Module{{ // see issue-12
 			Import: "go.opentelemetry.io/collector/receiver/jaegerreceiver",
+			GoMod:  "go.opentelemetry.io/collector v0.21.0",
 		}},
 	}
 
@@ -77,7 +77,6 @@ func TestModuleFromCore(t *testing.T) {
 
 	// verify
 	assert.True(t, strings.HasPrefix(cfg.Extensions[0].Name, "jaegerreceiver"))
-	assert.Empty(t, cfg.Extensions[0].GoMod)
 }
 
 func TestInvalidModule(t *testing.T) {