diff --git a/include/libcamera/internal/ipa_module.h b/include/libcamera/internal/ipa_module.h
index 7c49d3f34..15f19492c 100644
--- a/include/libcamera/internal/ipa_module.h
+++ b/include/libcamera/internal/ipa_module.h
@@ -29,7 +29,7 @@ public:
 	bool isValid() const;
 
 	const struct IPAModuleInfo &info() const;
-	const std::vector<uint8_t> signature() const;
+	const std::vector<uint8_t> &signature() const;
 	const std::string &path() const;
 
 	bool load();
diff --git a/src/libcamera/ipa_module.cpp b/src/libcamera/ipa_module.cpp
index 9ca74be6e..e6ea61e44 100644
--- a/src/libcamera/ipa_module.cpp
+++ b/src/libcamera/ipa_module.cpp
@@ -373,7 +373,7 @@ const struct IPAModuleInfo &IPAModule::info() const
  *
  * \return The IPA module signature
  */
-const std::vector<uint8_t> IPAModule::signature() const
+const std::vector<uint8_t> &IPAModule::signature() const
 {
 	return signature_;
 }