diff --git a/lib/checkio.cpp b/lib/checkio.cpp
index 05efdf4e8..b61af0dc8 100644
--- a/lib/checkio.cpp
+++ b/lib/checkio.cpp
@@ -770,7 +770,7 @@ void CheckIO::checkFormatString(const Token * const tok,
                                                 invalidScanfArgTypeError_int(tok, numFormat, specifier, &argInfo, true);
                                             break;
                                         default:
-                                            if (argInfo.typeToken->str() != "int")
+                                            if (argInfo.typeToken->str() != "int" || !argInfo.typeToken->isUnsigned())
                                                 invalidScanfArgTypeError_int(tok, numFormat, specifier, &argInfo, true);
                                             else if (typesMatch(argInfo.typeToken->originalName(), "size_t") ||
                                                      typesMatch(argInfo.typeToken->originalName(), "ptrdiff_t") ||
diff --git a/test/testio.cpp b/test/testio.cpp
index 08d2509fe..6de795af4 100644
--- a/test/testio.cpp
+++ b/test/testio.cpp
@@ -1186,8 +1186,8 @@ private:
         TEST_SCANF("%x", "unsigned int", "short");
         TEST_SCANF("%x", "unsigned int", "signed short");
         TEST_SCANF("%x", "unsigned int", "unsigned short");
-        // TEST_SCANF("%x", "unsigned int", "int");
-        // TODO TEST_SCANF("%x", "unsigned int", "signed int");
+        TEST_SCANF("%x", "unsigned int", "int");
+        TEST_SCANF("%x", "unsigned int", "signed int");
         TEST_SCANF("%x", "unsigned int", "long");
         TEST_SCANF("%x", "unsigned int", "signed long");
         TEST_SCANF("%x", "unsigned int", "unsigned long");