diff --git a/C/Android.bp b/C/Android.bp
index 803ecff..1ee4798 100644
--- a/C/Android.bp
+++ b/C/Android.bp
@@ -8,7 +8,7 @@
     stl: "none",
 
     cflags: ["-D_7ZIP_ST", "-Wno-empty-body"],
-    clang_cflags: ["-Wno-self-assign"],
+    clang_cflags: ["-Wno-self-assign", "-Werror"],
 
     export_include_dirs: ["."],
 
diff --git a/C/Lzma2Enc.c b/C/Lzma2Enc.c
index 34a97f3..1627bae 100644
--- a/C/Lzma2Enc.c
+++ b/C/Lzma2Enc.c
@@ -238,7 +238,7 @@
     if (temp > p->lzmaProps.reduceSize)
     {
       UInt64 numBlocks = temp / p->blockSize;
-      if (numBlocks < t2)
+      if (t2 >= 0 && numBlocks < (UInt64) t2)
       {
         t2 = (UInt32)numBlocks;
         t3 = t1 * t2;