diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index a174c3eb3..90c5b023e 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -3359,6 +3359,11 @@ void CheckOther::complexDuplicateExpressionCheck(const std::list<const Function*
 
 static bool astIsFloat(const Token *tok)
 {
+    if (tok->astOperand1() && astIsFloat(tok->astOperand1()))
+        return true;
+    if (tok->astOperand2() && astIsFloat(tok->astOperand2()))
+        return true;
+
     // TODO: check function calls, struct members, arrays, etc also
     return tok->variable() && Token::Match(tok->variable()->typeStartToken(), "float|double");
 }
diff --git a/test/testother.cpp b/test/testother.cpp
index d664a2d30..297eb49f6 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -4872,6 +4872,13 @@ private:
 
         check("float f(float x) { return x-x; }"); // ticket #4485 (Inf)
         ASSERT_EQUALS("", errout.str());
+
+        check("float f(float x) { return (X double)x == (X double)x; }", NULL, false, false, false, false);
+        ASSERT_EQUALS("", errout.str());
+
+        check("struct X { float f; };\n"
+              "float f(struct X x) { return x.f == x.f; }");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void duplicateExpression3() {