diff --git a/scripts/run_cli_tests.sh b/scripts/run_cli_tests.sh
index 6ce3ab4..ed4483c 100755
--- a/scripts/run_cli_tests.sh
+++ b/scripts/run_cli_tests.sh
@@ -48,4 +48,7 @@ if [[ ! -S "$socket_path" ]]; then
 fi
 
 url="http://localhost/tests/cli_runner.uce?action=${action}&include_kill=${include_kill}&skip_local_service_pages=${skip_local_service_pages}"
-exec curl -sS --fail-with-body --unix-socket "$socket_path" "$url"
+curl -sS --fail-with-body --unix-socket "$socket_path" "$url"
+if [[ "$action" == "run" ]]; then
+	scripts/test_dependency_invalidation.sh
+fi
diff --git a/scripts/test_dependency_invalidation.sh b/scripts/test_dependency_invalidation.sh
new file mode 100755
index 0000000..d592443
--- /dev/null
+++ b/scripts/test_dependency_invalidation.sh
@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+set -euo pipefail
+cd "$(dirname "$0")/.."
+
+test_name="dependency-cache-test-$$"
+source_dir="site/$test_name"
+cache_dir="${BIN_DIRECTORY:-/tmp/uce/work}$(pwd)/$source_dir"
+
+cleanup() {
+	rm -rf "$source_dir" "$cache_dir"
+}
+trap cleanup EXIT
+mkdir -p "$source_dir"
+
+printf '%s\n' \
+	'#ifndef UCE_DEPENDENCY_CACHE_CHILD' \
+	'#define UCE_DEPENDENCY_CACHE_CHILD' \
+	'String dependency_cache_marker() { return("dependency-marker-a"); }' \
+	'#endif' >"$source_dir/child.uce"
+printf '%s\n' \
+	'#load "child.uce"' \
+	'CLI(Request& context) { print(dependency_cache_marker()); }' \
+	'RENDER(Request& context) { print(dependency_cache_marker()); }' >"$source_dir/parent.uce"
+
+first=$(scripts/uce-cli "/$test_name/parent.uce")
+if [[ "$first" != *dependency-marker-a* ]]; then
+	echo "dependency invalidation setup failed: $first" >&2
+	exit 1
+fi
+
+sed -i 's/dependency-marker-a/dependency-marker-b/' "$source_dir/child.uce"
+second=$(scripts/uce-cli "/$test_name/parent.uce")
+if [[ "$second" != *dependency-marker-b* ]]; then
+	echo "loaded dependency change did not recompile parent: $second" >&2
+	exit 1
+fi
+
+echo "dependency invalidation passed"
diff --git a/site/doc/pages/load.txt b/site/doc/pages/load.txt
index ec11054..cc1ca3a 100644
--- a/site/doc/pages/load.txt
+++ b/site/doc/pages/load.txt
@@ -12,6 +12,8 @@ Includes another UCE file.
 
 Use `#load` when you want the current file to pull in declarations or reusable content from another UCE source file.
 
+Loaded sources are tracked transitively. Changing a direct or nested `#load` dependency invalidates and recompiles the entry unit before its next execution.
+
 
 :example
 // #load "file.uce" includes another unit at COMPILE time (a preprocessor directive,
diff --git a/src/lib/compiler.cpp b/src/lib/compiler.cpp
index a0fb5c5..c2934f1 100644
--- a/src/lib/compiler.cpp
+++ b/src/lib/compiler.cpp
@@ -87,6 +87,55 @@ StringMap compiler_parse_unit_metadata(String content)
 	return(metadata);
 }
 
+StringList compiler_unit_load_paths(String file_name, String content)
+{
+	StringList paths;
+	u64 line_start = 0;
+	while(line_start < content.length())
+	{
+		u64 line_end = content.find("\n", line_start);
+		if(line_end == String::npos)
+			break;
+		String line = content.substr(line_start, line_end - line_start);
+		if(str_starts_with(line, "#load "))
+		{
+			u64 first_quote = line.find('"', 6);
+			u64 second_quote = first_quote == String::npos ? String::npos : line.find('"', first_quote + 1);
+			if(first_quote != String::npos && second_quote != String::npos)
+			{
+				String loaded = line.substr(first_quote + 1, second_quote - first_quote - 1);
+				if(loaded != "")
+					paths.push_back(loaded[0] == '/' ? loaded : expand_path(loaded, dirname(file_name)));
+			}
+		}
+		line_start = line_end + 1;
+	}
+	return(paths);
+}
+
+void compiler_append_unit_source_signature(String file_name, std::set<String>& visited, String& signature)
+{
+	String normalized = path_real(file_name);
+	if(normalized == "")
+		normalized = file_name;
+	if(visited.find(normalized) != visited.end())
+		return;
+	visited.insert(normalized);
+
+	String content = file_get_contents(file_name);
+	signature += normalized + ":" + gen_sha1(content) + "\n";
+	for(String loaded : compiler_unit_load_paths(file_name, content))
+		compiler_append_unit_source_signature(loaded, visited, signature);
+}
+
+String compiler_unit_source_signature(String file_name)
+{
+	std::set<String> visited;
+	String signature = "uce-load-graph-v1\n";
+	compiler_append_unit_source_signature(file_name, visited, signature);
+	return(gen_sha1(signature));
+}
+
 String compiler_unit_input_signature(Request* context, SharedUnit* su)
 {
 	if(!context || !su || !file_exists(su->file_name))
@@ -94,7 +143,7 @@ String compiler_unit_input_signature(Request* context, SharedUnit* su)
 
 	String setup_template = context->server->config["COMPILER_SYS_PATH"] + "/" + context->server->config["SETUP_TEMPLATE"];
 	return(
-		gen_sha1(file_get_contents(su->file_name)) + ":" +
+		compiler_unit_source_signature(su->file_name) + ":" +
 		gen_sha1(file_get_contents(setup_template)) + ":" +
 		std::to_string(UCE_UNIT_ABI_VERSION)
 	);