diff --git a/lib/Makefile b/lib/Makefile
index 9ca53af..8ee4b7e 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -29,7 +29,7 @@ depends.mk: *.cc
 	echo "namespace crucible { const char *VERSION = \"$(TAG)\"; }" > .version.new.cc
 	mv -f .version.new.cc .version.cc
 
--include depends.mk
+include depends.mk
 
 %.o: %.cc ../include/crucible/%.h
 	$(CXX) $(CXXFLAGS) -fPIC -o $@ -c $<
diff --git a/src/Makefile b/src/Makefile
index 3a69c9a..c720c6a 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -18,7 +18,7 @@ bees-version.c: Makefile *.cc *.h
 	echo "const char *BEES_VERSION = \"$(shell git describe --always --dirty || echo UNKNOWN)\";" > bees-version.new.c
 	mv -f bees-version.new.c bees-version.c
 
--include depends.mk
+include depends.mk
 
 %.o: %.cc %.h
 	$(CXX) $(CXXFLAGS) -o "$@" -c "$<"
diff --git a/test/Makefile b/test/Makefile
index c0091e1..532f617 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -21,7 +21,7 @@ depends.mk: *.cc
 	for x in *.cc; do $(CXX) $(CXXFLAGS) -M "$$x"; done > depends.mk.new
 	mv -fv depends.mk.new depends.mk
 
--include depends.mk
+include depends.mk
 
 %.o: %.cc %.h ../makeflags
 	-echo "Implicit rule %.o: %.cc" >&2