diff --git a/.github/workflows/generic-dev.yml b/.github/workflows/generic-dev.yml
index d6e9b44b426..14e2e281fb4 100644
--- a/.github/workflows/generic-dev.yml
+++ b/.github/workflows/generic-dev.yml
@@ -62,7 +62,7 @@ jobs:
     # zbufftest-dll : test that a user program can link to multi-threaded libzstd without specifying -pthread
 
   gcc-8-asan-ubsan-testzstd:
-    runs-on: ubuntu-16.04 # fails on 18.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
     - name: gcc-8 + ASan + UBSan + Test Zstd
diff --git a/contrib/seekable_format/tests/seekable_tests.c b/contrib/seekable_format/tests/seekable_tests.c
index 1d8871c26e1..a482638b918 100644
--- a/contrib/seekable_format/tests/seekable_tests.c
+++ b/contrib/seekable_format/tests/seekable_tests.c
@@ -103,7 +103,7 @@ int main(int argc, const char** argv)
             '\x00',
             '\x00',
             '\x00',
-            ';',
+            (uint8_t)('\x03'),
             (uint8_t)('\xb1'),
             (uint8_t)('\xea'),
             (uint8_t)('\x92'),
diff --git a/contrib/seekable_format/zstdseek_decompress.c b/contrib/seekable_format/zstdseek_decompress.c
index 748e76a3f6a..b78c6341ad9 100644
--- a/contrib/seekable_format/zstdseek_decompress.c
+++ b/contrib/seekable_format/zstdseek_decompress.c
@@ -332,7 +332,7 @@ static size_t ZSTD_seekable_loadSeekTable(ZSTD_seekable* zs)
         checksumFlag = sfd >> 7;
 
         /* check reserved bits */
-        if ((checksumFlag >> 2) & 0x1f) {
+        if ((sfd >> 2) & 0x1f) {
             return ERROR(corruption_detected);
     }   }