diff --git a/pkg/probo/document_service.go b/pkg/probo/document_service.go
index bd62c2912..89756622e 100644
--- a/pkg/probo/document_service.go
+++ b/pkg/probo/document_service.go
@@ -506,9 +506,9 @@ func (s DocumentService) generateChangelog(
 		"changelog_generator",
 		s.svc.llmClient,
 		agent.WithInstructions(changelogGeneratorSystemPrompt),
-		agent.WithModel(s.svc.llmModel),
-		agent.WithTemperature(s.svc.llmTemperature),
-		agent.WithMaxTokens(s.svc.llmMaxTokens),
+		agent.WithModel(s.svc.llmConfig.Model),
+		agent.WithTemperature(s.svc.llmConfig.Temperature),
+		agent.WithMaxTokens(s.svc.llmConfig.MaxTokens),
 	)
 
 	result, err := ag.Run(
diff --git a/pkg/probo/service.go b/pkg/probo/service.go
index 42965c867..2a95f0856 100644
--- a/pkg/probo/service.go
+++ b/pkg/probo/service.go
@@ -59,6 +59,14 @@ type ExportService interface {
 }
 
 type (
+	// LLMConfig holds the model parameters used by the agents the probo
+	// service runs.
+	LLMConfig struct {
+		Model       string
+		Temperature float64
+		MaxTokens   int
+	}
+
 	Service struct {
 		pg                                    *pg.Client
 		s3                                    *s3.Client
@@ -67,9 +75,7 @@ type (
 		baseURL                               string
 		tokenSecret                           string
 		llmClient                             *llm.Client
-		llmModel                              string
-		llmTemperature                        float64
-		llmMaxTokens                          int
+		llmConfig                             LLMConfig
 		html2pdfConverter                     *html2pdf.Converter
 		acmeService                           *certmanager.ACMEService
 		fileManager                           *filemanager.Service
@@ -129,9 +135,7 @@ func NewService(
 	baseURL string,
 	tokenSecret string,
 	llmClient *llm.Client,
-	llmModel string,
-	llmTemperature float64,
-	llmMaxTokens int,
+	llmConfig LLMConfig,
 	html2pdfConverter *html2pdf.Converter,
 	acmeService *certmanager.ACMEService,
 	fileManagerService *filemanager.Service,
@@ -157,9 +161,7 @@ func NewService(
 		baseURL:                 baseURL,
 		tokenSecret:             tokenSecret,
 		llmClient:               llmClient,
-		llmModel:                llmModel,
-		llmTemperature:          llmTemperature,
-		llmMaxTokens:            llmMaxTokens,
+		llmConfig:               llmConfig,
 		html2pdfConverter:       html2pdfConverter,
 		acmeService:             acmeService,
 		fileManager:             fileManagerService,
diff --git a/pkg/probod/probod.go b/pkg/probod/probod.go
index a18ff1a96..619b6db75 100644
--- a/pkg/probod/probod.go
+++ b/pkg/probod/probod.go
@@ -39,6 +39,7 @@ import (
 	"go.gearno.de/kit/pg"
 	"go.gearno.de/kit/unit"
 	"go.gearno.de/kit/worker"
+	"go.gearno.de/x/ref"
 	"go.opentelemetry.io/otel/trace"
 	"go.probo.inc/probo/packages/emails"
 	"go.probo.inc/probo/pkg/accessreview"
@@ -507,9 +508,11 @@ func (impl *Implm) Run(
 		baseURL.String(),
 		impl.cfg.Auth.Cookie.Secret,
 		proboLLMClient,
-		proboAgentCfg.ModelName,
-		*proboAgentCfg.Temperature,
-		*proboAgentCfg.MaxTokens,
+		probo.LLMConfig{
+			Model:       proboAgentCfg.ModelName,
+			Temperature: ref.UnrefOrZero(proboAgentCfg.Temperature),
+			MaxTokens:   ref.UnrefOrZero(proboAgentCfg.MaxTokens),
+		},
 		html2pdfConverter,
 		acmeService,
 		fileManagerService,
@@ -790,8 +793,8 @@ func (impl *Implm) Run(
 		evidenceDescriberLLMClient,
 		evidencedescriber.Config{
 			Model:     evidenceDescriberAgentCfg.ModelName,
-			Temp:      *evidenceDescriberAgentCfg.Temperature,
-			MaxTokens: *evidenceDescriberAgentCfg.MaxTokens,
+			Temp:      ref.UnrefOrZero(evidenceDescriberAgentCfg.Temperature),
+			MaxTokens: ref.UnrefOrZero(evidenceDescriberAgentCfg.MaxTokens),
 		},
 	)
 	evidenceDescriptionWorker := probo.NewEvidenceDescriptionWorker(
diff --git a/pkg/probodconfig/llm_config.go b/pkg/probodconfig/llm_config.go
index b745bde31..3cda73fde 100644
--- a/pkg/probodconfig/llm_config.go
+++ b/pkg/probodconfig/llm_config.go
@@ -96,12 +96,8 @@ func (c *AgentsConfig) ResolveAgent(agent LLMAgentConfig) LLMAgentConfig {
 		agent.ModelName = c.Default.ModelName
 	}
 
-	if agent.Temperature == nil {
-		agent.Temperature = c.Default.Temperature
-	}
-
-	if agent.MaxTokens == nil {
-		agent.MaxTokens = c.Default.MaxTokens
+	if agent.MaxTokens == nil && c.Default.MaxTokens != nil {
+		agent.MaxTokens = new(*c.Default.MaxTokens)
 	}
 
 	return agent