diff --git a/unittests/ADT/APIntTest.cpp b/unittests/ADT/APIntTest.cpp
index dcafae2..8ff7d1d 100644
--- a/unittests/ADT/APIntTest.cpp
+++ b/unittests/ADT/APIntTest.cpp
@@ -176,4 +176,13 @@
   EXPECT_EQ(zero, one.srem(neg_one));
 }
 
+TEST(APIntTest, fromString) {
+  EXPECT_EQ(APInt(1, 0), APInt(1, "0", 1, 10));
+  EXPECT_EQ(APInt(1, 1), APInt(1, "1", 1, 10));
+  EXPECT_EQ(APInt(1, 1), APInt(1, "-1", 2, 10));
+  EXPECT_EQ(APInt(1, 1), APInt(1, "1", 1, 2));
+  EXPECT_EQ(APInt(1, 1), APInt(1, "1", 1, 8));
+  EXPECT_EQ(APInt(1, 1), APInt(1, "1", 1, 16));
+}
+
 }