diff --git a/Makefile b/Makefile
index 0266300..fec241b 100644
--- a/Makefile
+++ b/Makefile
@@ -63,6 +63,8 @@ clean:
 indent:
 	clang-format -i -style="{BasedOnStyle: Google, IndentWidth: 8, UseTab: Always, AllowShortIfStatementsOnASingleLine: false, ColumnLimit: 0, ContinuationIndentWidth: 8, SpaceAfterCStyleCast: true, IndentCaseLabels: false, AllowShortBlocksOnASingleLine: false, AllowShortFunctionsOnASingleLine: false}" $(C) $(H)
 
+geometry.o: clipper/clipper.hpp
+
 TESTS = $(wildcard tests/*/out/*.json)
 SPACE = $(NULL) $(NULL)