diff --git a/src/igo.c b/src/igo.c
index adc2800..3c5ddba 100644
--- a/src/igo.c
+++ b/src/igo.c
@@ -8,6 +8,10 @@ int igo_init (
     /* --- inouts --- */
     igo_common* igo_cm
 ) {
+    if (igo_cm == NULL) {
+        return 0;
+    }
+
     igo_cm->cholmod_cm = malloc(sizeof(cholmod_common));
     cholmod_start(igo_cm->cholmod_cm);
 
@@ -44,6 +48,9 @@ int igo_finish (
     /* --- inouts --- */
     igo_common* igo_cm
 ) {
+    if (igo_cm == NULL) {
+        return 1;
+    }
     igo_free_sparse(&(igo_cm->A), igo_cm);
     igo_free_dense(&(igo_cm->b), igo_cm);
     igo_free_factor(&(igo_cm->L), igo_cm);
diff --git a/src/igo.h b/src/igo.h
index 0194c72..efe9d58 100644
--- a/src/igo.h
+++ b/src/igo.h
@@ -103,11 +103,13 @@ typedef struct igo_common_struct {
 /* Primary functions */
 /* ---------------------------------------------------------- */
 
+/* Returns 0 if given a NULL pointer, 1 otherwise. */
 int igo_init (
     /* --- inouts --- */
     igo_common* igo_cm
 ) ;
 
+/* Always succeeds and returns 1. Attempting to finish a NULL pointer performs no operation on it instead. */
 int igo_finish (
     /* --- inouts --- */
     igo_common* igo_cm
diff --git a/tests/test_igo_common.cpp b/tests/test_igo_common.cpp
new file mode 100644
index 0000000..86e4246
--- /dev/null
+++ b/tests/test_igo_common.cpp
@@ -0,0 +1,55 @@
+#include <gtest/gtest.h>
+
+extern "C" {
+#include <igo.h>
+}
+
+TEST(CommonTests, TestInitTypical) {
+    igo_common* igo_cm = (igo_common*) malloc(sizeof(igo_common));
+    int ret = igo_init(igo_cm);
+    ASSERT_EQ(ret, 1);
+    ASSERT_NE(igo_cm, (void*)NULL);
+    // check cholmod initialization
+    ASSERT_NE(igo_cm->cholmod_cm, (void*)NULL);
+    ASSERT_EQ(igo_cm->cholmod_cm->status, 0);
+    // check matrices
+    ASSERT_NE(igo_cm->A, (void*)NULL);
+    ASSERT_NE(igo_cm->b, (void*)NULL);
+    ASSERT_NE(igo_cm->L, (void*)NULL);
+    ASSERT_NE(igo_cm->x, (void*)NULL);
+    ASSERT_NE(igo_cm->y, (void*)NULL);
+    // cleanup
+    cholmod_free_sparse(&igo_cm->A->A, igo_cm->cholmod_cm);
+    cholmod_free_dense(&igo_cm->b->B, igo_cm->cholmod_cm);
+    cholmod_free_factor(&igo_cm->L->L, igo_cm->cholmod_cm);
+    cholmod_free_dense(&igo_cm->x->B, igo_cm->cholmod_cm);
+    cholmod_free_dense(&igo_cm->y->B, igo_cm->cholmod_cm);
+    free(igo_cm->A);
+    free(igo_cm->b);
+    free(igo_cm->L);
+    free(igo_cm->x);
+    free(igo_cm->y);
+    cholmod_finish(igo_cm->cholmod_cm);
+    free(igo_cm);
+}
+
+TEST(CommonTests, TestFinishTypical) {
+    igo_common* igo_cm = (igo_common*) malloc(sizeof(igo_common));
+    igo_init(igo_cm);
+    int ret = igo_finish(igo_cm);
+    ASSERT_EQ(ret, 1);
+    ASSERT_EQ(igo_cm->cholmod_cm, (void*)NULL);
+    free(igo_cm);
+}
+
+TEST(CommonTests, TestFinishNull) {
+    igo_common* igo_cm = NULL;
+    int ret = igo_finish(igo_cm);
+    ASSERT_EQ(ret, 1);
+}
+
+TEST(CommonTests, TestInitNull) {
+    igo_common* igo_cm = NULL;
+    int ret = igo_init(igo_cm);
+    ASSERT_EQ(ret, 0);
+}