diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index da1c5a34f..cf43bff0f 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -3126,6 +3126,8 @@ void CheckOther::checkKnownArgument()
                     }
                     return ChildrenToVisit::none;
                 }
+                if (Token::simpleMatch(child->previous(), "sizeof ("))
+                    return ChildrenToVisit::none;
                 return ChildrenToVisit::op1_and_op2;
             });
             if (varexpr.empty())
diff --git a/test/testother.cpp b/test/testother.cpp
index 218e41909..a8c5719d1 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -8830,6 +8830,13 @@ private:
               "}\n");
         ASSERT_EQUALS("", errout.str());
 
+        check("char *yytext;\n"
+              "void re_init_scanner() {\n"
+              "  int size = 256;\n"
+              "  yytext = xmalloc(size * sizeof *yytext);\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+
         // #8986
         check("void f(int);\n"
               "void g() {\n"