diff --git a/src/compress.h b/src/compress.h
index ed7ce7058..c8f2389f2 100644
--- a/src/compress.h
+++ b/src/compress.h
@@ -7,7 +7,7 @@
 
 namespace maxcso {
 
-static const char *VERSION = "1.4.2";
+static const char *VERSION = "1.4.3";
 
 struct Task;
 
diff --git a/src/input.cpp b/src/input.cpp
index 23e00e1f1..2048423af 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -75,7 +75,7 @@ void Input::DetectFormat() {
 				csoBlockSize_ = header->sector_size;
 
 				csoBlockShift_ = 0;
-				for (uint32_t i = header->sector_size; i > 0; i >>= 1) {
+				for (uint32_t i = header->sector_size; i > 1; i >>= 1) {
 					++csoBlockShift_;
 				}