diff --git a/include/chibi/gc_heap.h b/include/chibi/gc_heap.h
index eacf6b2f..3540f80b 100644
--- a/include/chibi/gc_heap.h
+++ b/include/chibi/gc_heap.h
@@ -7,6 +7,8 @@
 
 #include "chibi/sexp.h"
 
+#if SEXP_USE_IMAGE_LOADING
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -98,4 +100,6 @@ SEXP_API char* sexp_load_image_err();
 }
 #endif
 
+#endif  /* SEXP_USE_IMAGE_LOADING */
+
 #endif  /* ! SEXP_GC_HEAP_H */