diff --git a/cache.c b/cache.c
index 40c6f54..43bb5c6 100644
--- a/cache.c
+++ b/cache.c
@@ -49,6 +49,9 @@ pkg_cache_lookup(const char *id)
 void
 pkg_cache_add(pkg_t *pkg)
 {
+	if (pkg == NULL)
+		return;
+
 	pkg_ref(pkg);
 
 	pkg_node_insert(&pkg->cache_iter, pkg, &pkg_cache);
@@ -62,6 +65,9 @@ pkg_cache_add(pkg_t *pkg)
 void
 pkg_cache_remove(pkg_t *pkg)
 {
+	if (pkg == NULL)
+		return;
+
 	pkg_node_delete(&pkg->cache_iter, &pkg_cache);
 }
 
diff --git a/tests/run.sh.in b/tests/run.sh.in
index 6ba296f..f6a53a9 100644
--- a/tests/run.sh.in
+++ b/tests/run.sh.in
@@ -64,6 +64,8 @@ run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} --cflags --libs 'foo' '>' '1.2'
 	'-lfoo' '-I/usr/include/foo' '-fPIC'
 run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} --exists nonexistant; echo \$?" \
 	'1'
+run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} nonexistant; echo \$?" \
+	'1'
 run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} --exists 'foo > 1.2'; echo \$?" \
 	'0'
 run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} --exists 'foo > 1.2.3'; echo \$?" \