diff --git a/lib/library.cpp b/lib/library.cpp
index a69d1fcae..1fece701b 100644
--- a/lib/library.cpp
+++ b/lib/library.cpp
@@ -115,9 +115,9 @@ bool Library::load(const tinyxml2::XMLDocument &doc)
                         else if (strcmp(argnode->Name(), "not-uninit") == 0)
                             notuninit = true;
                         else if (strcmp(argnode->Name(), "formatstr") == 0)
-                            notuninit = true;
+                            formatstr = true;
                         else if (strcmp(argnode->Name(), "strz") == 0)
-                            notuninit = true;
+                            strz = true;
                         else
                             return false;
                     }
diff --git a/test/testlibrary.cpp b/test/testlibrary.cpp
index 9b742f689..74f958245 100644
--- a/test/testlibrary.cpp
+++ b/test/testlibrary.cpp
@@ -28,6 +28,7 @@ private:
     void run() {
         TEST_CASE(empty);
         TEST_CASE(function);
+        TEST_CASE(function_arg);
         TEST_CASE(memory);
     }
 
@@ -61,6 +62,35 @@ private:
         ASSERT(library.isnotnoreturn("foo"));
     }
 
+    void function_arg() {
+        const char xmldata[] = "<?xml version=\"1.0\"?>\n"
+                               "<def>\n"
+                               "  <function name=\"foo\">\n"
+                               "    <arg nr=\"1\">\n"
+                               "        <not-uninit/>\n"
+                               "    </arg>\n"
+                               "    <arg nr=\"2\">\n"
+                               "        <not-null/>\n"
+                               "    </arg>\n"
+                               "    <arg nr=\"3\">\n"
+                               "        <formatstr/>\n"
+                               "    </arg>\n"
+                               "    <arg nr=\"4\">\n"
+                               "        <strz/>\n"
+                               "    </arg>\n"
+                               "  </function>\n"
+                               "</def>";
+        tinyxml2::XMLDocument doc;
+        doc.Parse(xmldata, sizeof(xmldata));
+
+        Library library;
+        library.load(doc);
+        ASSERT_EQUALS(true, library.argumentChecks["foo"][1].notuninit);
+        ASSERT_EQUALS(true, library.argumentChecks["foo"][2].notnull);
+        ASSERT_EQUALS(true, library.argumentChecks["foo"][3].formatstr);
+        ASSERT_EQUALS(true, library.argumentChecks["foo"][4].strz);
+    }
+
     void memory() {
         const char xmldata[] = "<?xml version=\"1.0\"?>\n"
                                "<def>\n"