diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 951636ae7..c715282a1 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -4662,6 +4662,8 @@ static void valueFlowAfterCondition(TokenList *tokenlist,
         ValueFlow::Value false_value;
         const Token *vartok = parseCompareInt(tok, true_value, false_value);
         if (vartok) {
+            if (vartok->hasKnownValue())
+                return cond;
             if (vartok->str() == "=" && vartok->astOperand1() && vartok->astOperand2())
                 vartok = vartok->astOperand1();
             cond.true_values.push_back(true_value);
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index f56e91340..897a28d1c 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -2633,6 +2633,16 @@ private:
                "    }\n"
                "}\n";
         ASSERT_EQUALS(true, testValueOfXKnown(code, 7U, 0));
+
+        code = "void f(std::vector<int> v) {\n"
+               "    if (v.size() == 3) {\n"
+               "        if (v.size() == 1) {\n"
+               "            int x = 1;\n"
+               "            int a = x;\n"
+               "        }\n"
+               "    }\n"
+               "}\n";
+        ASSERT_EQUALS(true, testValueOfXKnown(code, 5U, 1));
     }
 
     void valueFlowAfterConditionSeveralNot() {