diff --git a/libguile/whippet/embed.am b/libguile/whippet/embed.am
index 7bf3a7120..12200c693 100644
--- a/libguile/whippet/embed.am
+++ b/libguile/whippet/embed.am
@@ -149,7 +149,7 @@ WHIPPET_CPPFLAGS_heap_conservative_parallel_generational_mmc = \
   -DGC_CONSERVATIVE_ROOTS=1 -DGC_CONSERVATIVE_TRACE=1 -DGC_GENERATIONAL=1 -DGC_PARALLEL=1
 
 WHIPPET_CPPFLAGS    = $(WHIPPET_CPPFLAGS_$(subst -,_,$(WHIPPET_COLLECTOR)))
-WHIPPET_CPPFLAGS    += -I$(srcdir)/%D%/api
+WHIPPET_CPPFLAGS    += -I$(top_builddir) -I$(srcdir)/%D%/api
 WHIPPET_IMPL_CFLAGS = -fno-strict-aliasing
 WHIPPET_LIBS        = -lm