diff --git a/lib/checknullpointer.cpp b/lib/checknullpointer.cpp
index 11652d796..3e54b6b58 100644
--- a/lib/checknullpointer.cpp
+++ b/lib/checknullpointer.cpp
@@ -160,7 +160,7 @@ bool CheckNullPointer::isPointerDeRef(const Token *tok, bool &unknown)
     const Token* parent = tok->astParent();
     if (!parent)
         return false;
-    bool firstOperand = parent->astOperand1() == tok;
+    const bool firstOperand = parent->astOperand1() == tok;
     while (parent->str() == "(" && (parent->astOperand2() == nullptr && parent->strAt(1) != ")")) { // Skip over casts
         parent = parent->astParent();
         if (!parent)
@@ -172,7 +172,7 @@ bool CheckNullPointer::isPointerDeRef(const Token *tok, bool &unknown)
         return true;
 
     // array access
-    if (parent->str() == "[" && (!parent->astParent() || parent->astParent()->str() != "&"))
+    if (firstOperand && parent->str() == "[" && (!parent->astParent() || parent->astParent()->str() != "&"))
         return true;
 
     // address of member variable / array element
diff --git a/test/testnullpointer.cpp b/test/testnullpointer.cpp
index c61d7cde1..3f4794212 100644
--- a/test/testnullpointer.cpp
+++ b/test/testnullpointer.cpp
@@ -2353,6 +2353,11 @@ private:
               "}");
         ASSERT_EQUALS("[test.cpp:2]: (warning) Possible null pointer dereference if the default parameter value is used: p\n", errout.str());
 
+        check("void f(int *p = 0) {\n"
+              "    buf[p] = 0;\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+
         check("void f(int *p = 0) {\n"
               "    if (p != 0 && bar())\n"
               "      *p = 0;\n"