diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index 2788663b6..4bdcd576b 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -288,11 +288,9 @@ bool isVariableChanged(const Token *start, const Token *end, const unsigned int
                 const Token *parent = tok->astParent();
                 while (parent && parent->str() == ",")
                     parent = parent->astParent();
-                if (parent && parent->str() == "(") {
-                    if (parent->astOperand1() && parent->astOperand1()->isName() && !parent->astOperand1()->function())
-                        return true;
-                    // TODO: check if function parameter is non-const reference etc..
-                }
+                if (parent && Token::Match(parent->previous(), "%name% (") && !parent->previous()->function())
+                    return true;
+                // TODO: check if function parameter is non-const reference etc..
             }
 
             const Token *parent = tok->astParent();
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 513f9ab09..37294df9e 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -1692,6 +1692,15 @@ private:
                "}\n";
         ASSERT(isNotKnownValues(code, "<"));
 
+        code = "void f() {\n"
+               "  int x = 0;\n"
+               "  do {\n"
+               "    if (x < 0) {}\n"
+               "    fred.dostuff(x);\n"
+               "  } while (abc);\n"
+               "}\n";
+        ASSERT(isNotKnownValues(code, "<"));
+
         code = "void f() {\n"
                "  int x = 0;\n"
                "  if (y) { dostuff(x); }\n"