diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index 863d67675..082030325 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -1607,7 +1607,10 @@ bool CheckUninitVar::checkLoopBody(const Token *tok, const Variable& var, const
                                 assign = false;
                                 break;
                             } else if (tok2->str() == "(") {
-                                ++indentlevel;
+                                if (Token::Match(tok2->astOperand1(), "sizeof"))
+                                    tok2 = tok2->link();
+                                else
+                                    ++indentlevel;
                             } else if (tok2->str() == ")") {
                                 if (indentlevel <= 1U)
                                     break;
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index eebc4f554..66505bfae 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -3265,6 +3265,15 @@ private:
                         "    }\n"
                         "}");
         ASSERT_EQUALS("", errout.str());
+
+        checkUninitVar2("void f(void) {\n" // #5658
+                        "    struct Foo *foo;\n"
+                        "    while (true) {\n"
+                        "            foo = malloc(sizeof(*foo));\n"
+                        "            foo->x = 0;\n"
+                        "    }\n"
+                        "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void uninitvar2_4494() {