diff --git a/Documentation/runtime_configuration.rst b/Documentation/runtime_configuration.rst
index 5648db7d7..3146cdba6 100644
--- a/Documentation/runtime_configuration.rst
+++ b/Documentation/runtime_configuration.rst
@@ -19,6 +19,11 @@ order:
 - LIBCAMERA_SYSCONF_DIR/configuration.yaml
 - /etc/libcamera/configuration.yaml
 
+If LIBCAMERA_CONFIG_DIR environment variable is non-empty then it
+specifies additional directories where to look for the configuration
+file, before looking at the standard locations. It can be a single
+directory or multiple directories separated by colons.
+
 The default name of the configuration file, configuration.yaml, can be
 overridden in LIBCAMERA_CONFIG_NAME environment variable. The variable
 can specify just an alternative configuration file name to be looked up
diff --git a/src/libcamera/global_configuration.cpp b/src/libcamera/global_configuration.cpp
index efc293422..13305f8c0 100644
--- a/src/libcamera/global_configuration.cpp
+++ b/src/libcamera/global_configuration.cpp
@@ -67,11 +67,6 @@ bool GlobalConfiguration::loadFile(const std::filesystem::path &fileName)
 
 bool GlobalConfiguration::load()
 {
-	const std::vector<std::filesystem::path> globalConfigurationDirectories = {
-		std::filesystem::path(LIBCAMERA_SYSCONF_DIR),
-		std::filesystem::path(LIBCAMERA_DATA_DIR),
-	};
-
 	const char *libcameraConfigName =
 		utils::secure_getenv("LIBCAMERA_CONFIG_NAME");
 	if (!libcameraConfigName)
@@ -86,6 +81,17 @@ bool GlobalConfiguration::load()
 	if (configName.empty())
 		configName = std::filesystem::path("configuration.yaml");
 
+	const char *configDir = utils::secure_getenv("LIBCAMERA_CONFIG_DIR");
+	std::vector<std::filesystem::path> globalConfigurationDirectories;
+	if (configDir) {
+		for (auto const &path : utils::split(configDir, ":")) {
+			if (!path.empty())
+				globalConfigurationDirectories.push_back(path);
+		}
+	}
+	globalConfigurationDirectories.push_back(LIBCAMERA_SYSCONF_DIR);
+	globalConfigurationDirectories.push_back(LIBCAMERA_DATA_DIR);
+
 	std::filesystem::path userConfigurationDirectory;
 	const char *xdgConfigHome = utils::secure_getenv("XDG_CONFIG_HOME");
 	if (xdgConfigHome) {