diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index 8565a3242..8b826b6a1 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -1344,7 +1344,7 @@ static std::size_t estimateSize(const Type* type, const Settings* settings, cons
         else if (i->type() && i->type()->classScope)
             size = estimateSize(i->type(), settings, symbolDatabase, recursionDepth+1);
         else if (i->isStlStringType() || (i->isStlType() && Token::Match(i->typeStartToken(), "std :: %type% <") && !Token::simpleMatch(i->typeStartToken()->linkAt(3), "> ::")))
-            size = 16; // Just guess
+            size = 3 * settings->sizeof_pointer; // Just guess
         else
             size = symbolDatabase->sizeOfType(i->typeStartToken());
 
@@ -1385,7 +1385,7 @@ void CheckOther::checkPassByReference()
             // Ensure that it is a large object.
             if (!var->type()->classScope)
                 inconclusive = true;
-            else if (estimateSize(var->type(), _settings, symbolDatabase) <= 8)
+            else if (estimateSize(var->type(), _settings, symbolDatabase) <= 2 * _settings->sizeof_pointer)
                 continue;
         } else
             continue;
diff --git a/test/testother.cpp b/test/testother.cpp
index c00a53a6f..01a1d09c5 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -1551,14 +1551,49 @@ private:
         ASSERT_EQUALS("", errout.str());
 
         check("class X {\n"
-              "    uint64_t i;\n"
+              "    char a[1024];\n"
               "};\n"
               "class Y : X {\n"
-              "    uint64_t j;\n"
+              "    char b;\n"
+              "};\n"
+              "void f(Y y) {\n"
+              "}");
+        ASSERT_EQUALS("[test.cpp:7]: (performance) Function parameter 'y' should be passed by reference.\n", errout.str());
+
+        check("class X {\n"
+              "    void* a;\n"
+              "    void* b;\n"
+              "};\n"
+              "class Y {\n"
+              "    void* a;\n"
+              "    void* b;\n"
+              "    char c;\n"
               "};\n"
               "void f(X x, Y y) {\n"
               "}");
-        ASSERT_EQUALS("[test.cpp:7]: (performance) Function parameter 'y' should be passed by reference.\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:10]: (performance) Function parameter 'y' should be passed by reference.\n", errout.str());
+
+        const auto originalPlatform = _settings.platformType;
+
+        _settings.platform(cppcheck::Platform::Unix32);
+        check("class X {\n"
+              "    uint64_t a;\n"
+              "    uint64_t b;\n"
+              "};\n"
+              "void f(X x) {\n"
+              "}");
+        ASSERT_EQUALS("[test.cpp:5]: (performance) Function parameter 'x' should be passed by reference.\n", errout.str());
+
+        _settings.platform(cppcheck::Platform::Unix64);
+        check("class X {\n"
+              "    uint64_t a;\n"
+              "    uint64_t b;\n"
+              "};\n"
+              "void f(X x) {\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+
+        _settings.platform(originalPlatform);
     }
 
     void switchRedundantAssignmentTest() {