diff --git a/cmd/build.go b/cmd/build.go
index 25d13c932..7a545ead0 100644
--- a/cmd/build.go
+++ b/cmd/build.go
@@ -87,6 +87,13 @@ func runBuild(cmd *cobra.Command, _ []string, newClient ClientFactory) (err erro
 
 	// Load the Function at path, and if it is initialized, update it with
 	// pertinent values from the config.
+	//
+	// NOTE: the checks for .Changed and altered conditionals for defaults will
+	// be removed when Global Config is integreated, because the config object
+	// will at that time contain the final value for the attribute, taking into
+	// account whether or not the value was altered via flags or env variables.
+	// This condition is also only necessary for config members whose default
+	// value deviates from the zero value.
 	f, err := fn.NewFunction(config.Path)
 	if err != nil {
 		return
@@ -94,15 +101,17 @@ func runBuild(cmd *cobra.Command, _ []string, newClient ClientFactory) (err erro
 	if !f.Initialized() {
 		return fmt.Errorf("'%v' does not contain an initialized function", config.Path)
 	}
-	if config.Registry != "" {
+	if f.Registry == "" || cmd.Flags().Changed("registry") {
+		// Sets default AND accepts any user-provided overrides
 		f.Registry = config.Registry
 	}
+	if f.Builder == "" || cmd.Flags().Changed("builder") {
+		// Sets default AND accepts any user-provided overrides
+		f.Builder = config.Builder
+	}
 	if config.Image != "" {
 		f.Image = config.Image
 	}
-	if config.Builder != "" {
-		f.Builder = config.Builder
-	}
 
 	// Choose a builder based on the value of the --builder flag
 	var builder fn.Builder
diff --git a/cmd/deploy.go b/cmd/deploy.go
index 44bc14d62..24bcea2f6 100644
--- a/cmd/deploy.go
+++ b/cmd/deploy.go
@@ -128,15 +128,17 @@ func runDeploy(cmd *cobra.Command, _ []string, newClient ClientFactory) (err err
 	if !f.Initialized() {
 		return fmt.Errorf("'%v' does not contain an initialized function", config.Path)
 	}
-	if config.Registry != "" {
+	if f.Registry == "" || cmd.Flags().Changed("registry") {
+		// Sets default AND accepts any user-provided overrides
 		f.Registry = config.Registry
 	}
+	if f.Builder == "" || cmd.Flags().Changed("builder") {
+		// Sets default AND accepts any user-provided overrides
+		f.Builder = config.Builder
+	}
 	if config.Image != "" {
 		f.Image = config.Image
 	}
-	if config.Builder != "" {
-		f.Builder = config.Builder
-	}
 
 	f.Namespace, err = checkNamespaceDeploy(f.Namespace, config.Namespace)
 	if err != nil {