1 files changed, 2 insertions, 1 deletions
diff --git a/Makefile b/Makefile
index 8c4487dd0c..81a47b6132 100644
--- a/Makefile
+++ b/Makefile
@@ -3252,7 +3252,8 @@ t/helper/test-%$X: t/helper/test-%.o GIT-LDFLAGS $(GITLIBS) $(REFTABLE_TEST_LIB)
 check-sha1:: t/helper/test-tool$X
 	t/helper/test-sha1.sh
 
-SP_OBJ = $(patsubst %.o,%.sp,$(OBJECTS))
+SP_SRC = $(filter-out $(THIRD_PARTY_SOURCES),$(patsubst %.o,%.c,$(OBJECTS)))
+SP_OBJ = $(patsubst %.c,%.sp,$(SP_SRC))
 
 $(SP_OBJ): %.sp: %.c %.o $(GENERATED_H)
 	$(QUIET_SP)cgcc -no-compile $(ALL_CFLAGS) $(EXTRA_CPPFLAGS) \