diff --git a/analysis/tokenizers/exception/exception.go b/analysis/tokenizers/exception/exception.go
index 51da89ac..63f9897c 100644
--- a/analysis/tokenizers/exception/exception.go
+++ b/analysis/tokenizers/exception/exception.go
@@ -111,6 +111,9 @@ func ExceptionsTokenizerConstructor(config map[string]interface{}, cache *regist
 	if ok {
 		exceptions = append(exceptions, aexceptions...)
 	}
+	if len(exceptions) == 0 {
+		return nil, fmt.Errorf("no pattern found in 'exception' property")
+	}
 	exceptionPattern := strings.Join(exceptions, "|")
 	r, err := regexp.Compile(exceptionPattern)
 	if err != nil {
diff --git a/registry/tokenizer.go b/registry/tokenizer.go
index efd8339a..24b5bf93 100644
--- a/registry/tokenizer.go
+++ b/registry/tokenizer.go
@@ -38,7 +38,7 @@ func (c TokenizerCache) TokenizerNamed(name string, cache *Cache) (analysis.Toke
 	}
 	tokenizer, err := tokenizerConstructor(nil, cache)
 	if err != nil {
-		return nil, fmt.Errorf("error building tokenizer: %v", err)
+		return nil, fmt.Errorf("error building tokenizer '%s': %v", name, err)
 	}
 	c[name] = tokenizer
 	return tokenizer, nil
@@ -55,7 +55,7 @@ func (c TokenizerCache) DefineTokenizer(name string, typ string, config map[stri
 	}
 	tokenizer, err := tokenizerConstructor(config, cache)
 	if err != nil {
-		return nil, fmt.Errorf("error building tokenizer: %v", err)
+		return nil, fmt.Errorf("error building tokenizer '%s': %v", name, err)
 	}
 	c[name] = tokenizer
 	return tokenizer, nil