diff --git a/src/compiler/codegen/arm/ArchUtility.cc b/src/compiler/codegen/arm/ArchUtility.cc
index 52fb018..5e8fa20 100644
--- a/src/compiler/codegen/arm/ArchUtility.cc
+++ b/src/compiler/codegen/arm/ArchUtility.cc
@@ -455,7 +455,7 @@
 
     // Dump mapping table
     if (cUnit->mappingTable.size() > 0) {
-        std::string line(StringPrintf("\n    MappingTable %s%s_%s_mappingTable[%d] = {",
+        std::string line(StringPrintf("\n    MappingTable %s%s_%s_mappingTable[%zu] = {",
             descriptor.c_str(), name.c_str(), signature.c_str(), cUnit->mappingTable.size()));
         std::replace(line.begin(), line.end(), ';', '_');
         LOG(INFO) << line;
diff --git a/src/java_lang_System.cc b/src/java_lang_System.cc
index 985e753..78100cf 100644
--- a/src/java_lang_System.cc
+++ b/src/java_lang_System.cc
@@ -107,7 +107,7 @@
 void ThrowArrayStoreException_NotAnArray(const char* identifier, Object* array) {
   std::string actualType(PrettyTypeOf(array));
   Thread::Current()->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
-      "%s is not an array: %s", identifier, actualType.c_str());
+      "%s of type %s is not an array", identifier, actualType.c_str());
 }
 
 void System_arraycopy(JNIEnv* env, jclass, jobject javaSrc, jint srcPos, jobject javaDst, jint dstPos, jint length) {
@@ -128,11 +128,11 @@
   Object* srcObject = Decode<Object*>(env, javaSrc);
   Object* dstObject = Decode<Object*>(env, javaDst);
   if (!srcObject->IsArrayInstance()) {
-    ThrowArrayStoreException_NotAnArray("src", srcObject);
+    ThrowArrayStoreException_NotAnArray("source", srcObject);
     return;
   }
   if (!dstObject->IsArrayInstance()) {
-    ThrowArrayStoreException_NotAnArray("dst", dstObject);
+    ThrowArrayStoreException_NotAnArray("destination", dstObject);
     return;
   }
   Array* srcArray = srcObject->AsArray();