diff --git a/cpp/qrcodegen.cpp b/cpp/qrcodegen.cpp
index a5536d4..4736a40 100644
--- a/cpp/qrcodegen.cpp
+++ b/cpp/qrcodegen.cpp
@@ -238,7 +238,7 @@ int QrCode::getFormatBits(Ecc ecl) {
 		case Ecc::MEDIUM  :  return 0;
 		case Ecc::QUARTILE:  return 3;
 		case Ecc::HIGH    :  return 2;
-		default:  throw std::logic_error("Assertion error");
+		default:  throw std::logic_error("Unreachable");
 	}
 }
 
@@ -584,7 +584,7 @@ void QrCode::applyMask(int msk) {
 				case 5:  invert = x * y % 2 + x * y % 3 == 0;          break;
 				case 6:  invert = (x * y % 2 + x * y % 3) % 2 == 0;    break;
 				case 7:  invert = ((x + y) % 2 + x * y % 3) % 2 == 0;  break;
-				default:  throw std::logic_error("Assertion error");
+				default:  throw std::logic_error("Unreachable");
 			}
 			modules.at(y).at(x) = modules.at(y).at(x) ^ (invert & !isFunction.at(y).at(x));
 		}
diff --git a/typescript-javascript/qrcodegen.ts b/typescript-javascript/qrcodegen.ts
index 036fc9e..bc4c31d 100644
--- a/typescript-javascript/qrcodegen.ts
+++ b/typescript-javascript/qrcodegen.ts
@@ -454,7 +454,7 @@ namespace qrcodegen {
 						case 5:  invert = x * y % 2 + x * y % 3 == 0;                        break;
 						case 6:  invert = (x * y % 2 + x * y % 3) % 2 == 0;                  break;
 						case 7:  invert = ((x + y) % 2 + x * y % 3) % 2 == 0;                break;
-						default:  throw "Assertion error";
+						default:  throw "Unreachable";
 					}
 					if (!this.isFunction[y][x] && invert)
 						this.modules[y][x] = !this.modules[y][x];