diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 2135a42a3..4e875899f 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -6095,7 +6095,7 @@ bool Tokenizer::simplifyKnownVariables()
                     }
 
                     // array usage
-                    if (Token::Match(tok3, "( %varid% [", varid))
+                    if (Token::Match(tok3, "[(,] %varid% [+-*/[]", varid))
                     {
                         tok3 = tok3->next();
                         tok3->str(value);
diff --git a/test/testbufferoverrun.cpp b/test/testbufferoverrun.cpp
index f2dc3bad9..f20499378 100644
--- a/test/testbufferoverrun.cpp
+++ b/test/testbufferoverrun.cpp
@@ -1359,8 +1359,7 @@ private:
               "char str[i];\n"
               "fread(str,sizeof(char),i+1,fd);\n"
               "}\n");
-        ASSERT_EQUALS("", errout.str());	// catch changes
-        TODO_ASSERT_EQUALS("[test.cpp:5]: (error) Buffer access out-of-bounds\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:5]: (error) Buffer access out-of-bounds: str\n", errout.str());
 
         check("void f(FILE* fd)\n"
               "{\n"
@@ -1383,8 +1382,7 @@ private:
               "char str[i];\n"
               "fwrite(str,sizeof(char),i+1,fd);\n"
               "}\n");
-        ASSERT_EQUALS("", errout.str());	// catch changes
-        TODO_ASSERT_EQUALS("[test.cpp:5]: (error) Buffer access out-of-bounds\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:5]: (error) Buffer access out-of-bounds: str\n", errout.str());
 
         check("void f(FILE* fd)\n"
               "{\n"