diff --git a/lib/taskchampion.h b/lib/taskchampion.h
index f09bddfe1..fbdb42ab3 100644
--- a/lib/taskchampion.h
+++ b/lib/taskchampion.h
@@ -76,6 +76,9 @@
  */
 
 
+#ifndef TASKCHAMPION_H
+#define TASKCHAMPION_H
+
 #include <stdbool.h>
 #include <stdint.h>
 #include <time.h>
@@ -1009,3 +1012,5 @@ void tc_working_set_free(struct TCWorkingSet *ws);
 #ifdef __cplusplus
 } // extern "C"
 #endif // __cplusplus
+
+#endif /* TASKCHAMPION_H */
diff --git a/xtask/src/main.rs b/xtask/src/main.rs
index 6fd41b2d7..73ea71119 100644
--- a/xtask/src/main.rs
+++ b/xtask/src/main.rs
@@ -29,6 +29,7 @@ fn codegen() -> anyhow::Result<()> {
         .with_config(Config {
             header: Some(include_str!("../../lib/header-intro.h").into()),
             language: Language::C,
+            include_guard: Some("TASKCHAMPION_H".into()),
             cpp_compat: true,
             sys_includes: vec!["stdbool.h".into(), "stdint.h".into(), "time.h".into()],
             usize_is_size_t: true,