diff --git a/CHANGELOG.md b/CHANGELOG.md
index 605fff540..e28b1a9c6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+## [0.59.1]
+
+### Fixed
+- Fixed a bug in multi-turn tool calls for OpenAI models where an empty tools array could have been, which causes an API error.
+
 ## [0.59.0]
 
 ### Breaking Changes
diff --git a/Project.toml b/Project.toml
index 3ace6e71f..8cef265dd 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "PromptingTools"
 uuid = "670122d1-24a8-4d70-bfce-740807c42192"
 authors = ["J S @svilupp and contributors"]
-version = "0.59.0"
+version = "0.59.1"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
diff --git a/src/llm_openai.jl b/src/llm_openai.jl
index 2b76f1211..99f082591 100644
--- a/src/llm_openai.jl
+++ b/src/llm_openai.jl
@@ -56,11 +56,17 @@ function render(schema::AbstractOpenAISchema,
             end
             Dict("role" => role4render(schema, msg), "content" => content)
         elseif isaitoolrequest(msg)
-            Dict("role" => role4render(schema, msg), "content" => msg.content,
-                "tool_calls" => [Dict("id" => tool.tool_call_id, "type" => "function",
-                                     "function" => Dict("name" => tool.name,
-                                         "arguments" => tool.raw))
-                                 for tool in msg.tool_calls])
+            output = Dict{String, Any}(
+                "role" => role4render(schema, msg),
+                "content" => msg.content)
+            if !isempty(msg.tool_calls)
+                output["tool_calls"] = [Dict("id" => tool.tool_call_id,
+                                            "type" => "function",
+                                            "function" => Dict("name" => tool.name,
+                                                "arguments" => tool.raw))
+                                        for tool in msg.tool_calls]
+            end
+            output
         elseif istoolmessage(msg)
             content = msg.content isa AbstractString ? msg.content : string(msg.content)
             Dict("role" => role4render(schema, msg), "content" => content,
diff --git a/test/llm_openai.jl b/test/llm_openai.jl
index c329538a1..4439a1a39 100644
--- a/test/llm_openai.jl
+++ b/test/llm_openai.jl
@@ -196,6 +196,20 @@ using PromptingTools: pick_tokenizer, OPENAI_TOKEN_IDS_GPT35_GPT4, OPENAI_TOKEN_
     ]
     @test conversation == expected_output
 
+    # With empty tools
+    messages = [
+        SystemMessage("System message"),
+        UserMessage("User message"),
+        AIToolRequest(;content="content")
+    ]
+    conversation = render(schema, messages)
+    expected_output = Dict{String, Any}[
+        Dict("role" => "system", "content" => "System message"),
+        Dict("role" => "user", "content" => "User message"),
+        Dict("role" => "assistant", "content" => "content")
+    ]
+    @test conversation == expected_output
+
     # With a list of images and detail="low"
     messages = [
         SystemMessage("System message 2"),