diff --git a/scripts/test_dependency_invalidation.sh b/scripts/test_dependency_invalidation.sh
index 81961b6..47f5ae5 100755
--- a/scripts/test_dependency_invalidation.sh
+++ b/scripts/test_dependency_invalidation.sh
@@ -73,6 +73,16 @@ if [[ "$(http_marker)" != *"dependency-marker-a"* ]]; then
 	exit 1
 fi
 
+# Compiler source canonicalization must retain symlink-target identity while
+# avoiding realpath's repeated per-segment probes on ordinary source graphs.
+printf '%s\n' 'String symlink_dependency_marker() { return("symlink-marker-a"); }' >"$source_dir/symlink-target-a.uce"
+printf '%s\n' 'String symlink_dependency_marker() { return("symlink-marker-b"); }' >"$source_dir/symlink-target-b.uce"
+ln -s "symlink-target-a.uce" "$source_dir/symlink-child.uce"
+printf '%s\n' '#load "symlink-child.uce"' 'CLI(Request& context) { print(symlink_dependency_marker()); }' >"$source_dir/symlink-parent.uce"
+assert_marker symlink-parent symlink-marker-a
+ln -sfn "symlink-target-b.uce" "$source_dir/symlink-child.uce"
+assert_marker symlink-parent symlink-marker-b
+
 # HTTP entry units can resolve route/components dynamically. A changed dynamic
 # component must enter the demand-priority queue just like a changed entry unit;
 # otherwise a common dependency rebuild can leave the requested page stale for
diff --git a/src/lib/compiler.cpp b/src/lib/compiler.cpp
index 2b99d10..f5e2e38 100644
--- a/src/lib/compiler.cpp
+++ b/src/lib/compiler.cpp
@@ -158,6 +158,23 @@ bool compiler_source_readable(String file_name, const struct stat& info, int* re
 	return(error == 0);
 }
 
+String compiler_source_path_real(String file_name)
+{
+	int fd = open(file_name.c_str(), O_PATH | O_CLOEXEC);
+	if(fd < 0)
+		return(path_real(file_name));
+	String proc_path = "/proc/self/fd/" + std::to_string(fd);
+	char resolved[PATH_MAX];
+	ssize_t length = readlink(proc_path.c_str(), resolved, sizeof(resolved));
+	close(fd);
+	if(length <= 0 || length >= (ssize_t)sizeof(resolved))
+		return(path_real(file_name));
+	String result(resolved, (size_t)length);
+	if(str_ends_with(result, " (deleted)"))
+		return(path_real(file_name));
+	return(result);
+}
+
 UnitSourceSignatureEntry compiler_unit_source_entry(String file_name, bool allow_recent_stat)
 {
 	auto checked_at = std::chrono::steady_clock::now();
@@ -204,7 +221,7 @@ void compiler_append_unit_source_signature(String file_name, std::set<String>& v
 	bool recent = allow_recent_stat && compiler_recent_unit_source_entry(normalized, entry);
 	if(!recent)
 	{
-		normalized = path_real(file_name);
+		normalized = compiler_source_path_real(file_name);
 		if(normalized == "")
 			normalized = file_name;
 	}