diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index bf09904b2..8a9416415 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -4450,6 +4450,8 @@ static std::vector<const Token*> getConditions(const Token* tok, const char* op)
                 return false;
             if (tok2->hasKnownIntValue())
                 return false;
+            if (Token::Match(tok2, "%var%") && !astIsBool(tok2))
+                return false;
             return true;
         });
     }
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index f7153a86a..a986b5f38 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -6173,6 +6173,18 @@ private:
                "  ASSERT(!(t4 < t5) && t4 <= t5);\n"
                "}";
         valueOfTok(code, "<=");
+
+        code = "void f() {\n"
+               "    unsigned short Xoff = 10;\n"
+               "    unsigned short Nx = 0;\n"
+               "    int last;\n"
+               "    do {\n"
+               "        last = readData(0);\n"
+               "        if (last && (last - Xoff < Nx))\n"
+               "            Nx = last - Xoff;\n"
+               "    } while (last > 0);\n"
+               "}\n";
+        valueOfTok(code, "last");
     }
 
     void valueFlowHang() {