diff --git a/test/testtokenize.cpp b/test/testtokenize.cpp
index aef1476d3..6f604fb32 100644
--- a/test/testtokenize.cpp
+++ b/test/testtokenize.cpp
@@ -290,6 +290,7 @@ private:
         TEST_CASE(varidclass13);
         TEST_CASE(varidclass14);
         TEST_CASE(varidclass15);  // initializer list
+        TEST_CASE(varid_classnameshaddowsvariablename) // #3990
 
         TEST_CASE(file1);
         TEST_CASE(file2);
@@ -4717,6 +4718,22 @@ private:
         ASSERT_EQUALS(expected, tokenizeDebugListing(code));
     }
 
+    void varid_classnameshaddowsvariablename() {
+        const char code[] = "class Data;\n"
+                            "void strange_declarated(const Data& Data);\n"
+                            "void handleData(const Data& data) {\n"
+                            "    strange_declarated(data);\n"
+                            "}\n";
+        const char expected[] = "\n\n##file 0\n"
+                                "1: class Data ;\n"
+                                "2: void strange_declarated ( const Data & Data@1 ) ;\n"
+                                "3: void handleData ( const Data & data@2 ) {\n"
+                                "4: strange_declarated ( data@2 ) ;\n"
+                                "5: }\n";
+        ASSERT_EQUALS(expected, tokenizeDebugListing(code));
+
+    }
+
     void file1() {
         const char code[] = "a1\n"
                             "#file \"b\"\n"