diff --git a/pkg/templater/files.go b/pkg/templater/files.go
index cc95268..c5428ab 100644
--- a/pkg/templater/files.go
+++ b/pkg/templater/files.go
@@ -133,20 +133,20 @@ func (cf *ConfigFile) processHCLTemplate(file string, config []byte) (string, er
 
 	for n := range ctx.Variables {
 		if !hclsyntax.ValidIdentifier(n) {
-			panic(fmt.Errorf("invalid template variable name %q: must start with a letter, followed by zero or more letters, digits, and underscores", n))
+			return "", fmt.Errorf("invalid template variable name %q: must start with a letter, followed by zero or more letters, digits, and underscores", n)
 		}
 	}
 
 	for _, traversal := range expr.Variables() {
 		root := traversal.RootName()
 		if _, ok := ctx.Variables[root]; !ok {
-			panic(fmt.Errorf("vars map does not contain key %q, referenced at %s", root, traversal[0].SourceRange()))
+			return "", fmt.Errorf("vars map does not contain key %q, referenced at %s", root, traversal[0].SourceRange())
 		}
 	}
 
 	val, diags := expr.Value(ctx)
 	if diags.HasErrors() {
-		panic(diags.Error())
+		return "", diags
 	}
 
 	return val.AsString(), nil