diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8da286152..be2be1789 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,7 +24,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: make
-      run: make
+      run: make REDIS_CFLAGS='-Werror'
 
   build-macos-latest:
     runs-on: macos-latest
diff --git a/src/lzf_d.c b/src/lzf_d.c
index d44bfcc8d..5f55d471d 100644
--- a/src/lzf_d.c
+++ b/src/lzf_d.c
@@ -52,7 +52,7 @@
 #endif
 #endif
 
-#if defined(__GNUC__) && __GNUC__ >= 5
+#if defined(__GNUC__) && __GNUC__ >= 7
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
 #endif