diff --git a/lib/checkleakautovar.cpp b/lib/checkleakautovar.cpp
index 5d22da1ac..54236179f 100644
--- a/lib/checkleakautovar.cpp
+++ b/lib/checkleakautovar.cpp
@@ -543,13 +543,14 @@ void CheckLeakAutoVar::functionCall(const Token *tok, VarInfo *varInfo, const Va
         }
 
         if (Token::Match(arg, "%var% [-,)] !!.") || Token::Match(arg, "& %var%")) {
-
             // goto variable
             if (arg->str() == "&")
                 arg = arg->next();
 
+            bool isnull = arg->hasKnownIntValue() && arg->values.front().intvalue == 0;
+
             // Is variable allocated?
-            if (!af || af->arg == argNr)
+            if (!isnull && (!af || af->arg == argNr))
                 changeAllocStatus(varInfo, allocation, tok, arg);
         } else if (Token::Match(arg, "%name% (")) {
             const Library::AllocFunc* allocFunc = _settings->library.dealloc(arg);
diff --git a/test/testleakautovar.cpp b/test/testleakautovar.cpp
index 5af8f1238..5b9a21e3b 100644
--- a/test/testleakautovar.cpp
+++ b/test/testleakautovar.cpp
@@ -304,6 +304,12 @@ private:
               "    return p;\n"
               "}");
         ASSERT_EQUALS("[test.c:3]: (error) Returning/dereferencing 'p' after it is deallocated / released\n", errout.str());
+
+        check("void f(char *p) {\n"
+              "  if (!p) free(p);\n"
+              "  return p;\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void deallocuse5() {  // #4018