diff --git a/book_maker/translator/gemini_translator.py b/book_maker/translator/gemini_translator.py
index 0241d03..119114e 100644
--- a/book_maker/translator/gemini_translator.py
+++ b/book_maker/translator/gemini_translator.py
@@ -31,6 +31,11 @@ safety_settings = [
         "threshold": "BLOCK_MEDIUM_AND_ABOVE",
     },
 
+PROMPT_ENV_MAP = {
+    "user": "BBM_GEMINIAPI_USER_MSG_TEMPLATE",
+    "system": "BBM_GEMINIAPI_SYS_MSG",
+}
+
 GEMINIPRO_MODEL_LIST = [
     "gemini-1.5-pro",
     "gemini-1.5-pro-latest",
@@ -57,17 +62,33 @@ class Gemini(Base):
         self,
         key,
         language,
+        prompt_template=None,
+        prompt_sys_msg=None,
         temperature=1.0,
         interval=0.01,
         **kwargs,
     ) -> None:
         super().__init__(key, language)
         self.interval = interval
+        self.prompt = (
+            prompt_template
+            or environ.get(PROMPT_ENV_MAP["user"])
+            or self.DEFAULT_PROMPT
+        )
+        self.prompt_sys_msg = (
+            prompt_sys_msg
+            or environ.get(PROMPT_ENV_MAP["system"])
+            or None  # Allow None, but not empty string
+        )
+
         generation_config["temperature"] = temperature
+
+    def create_convo(self):
         model = genai.GenerativeModel(
             model_name=self.model,
             generation_config=generation_config,
             safety_settings=safety_settings,
+            system_instruction=self.prompt_sys_msg,
         )
         self.convo = model.start_chat()
         # print(model)  # Uncomment to debug and inspect the model details.