diff --git a/src/core/ext/transport/chttp2/transport/bin_decoder.c b/src/core/ext/transport/chttp2/transport/bin_decoder.c
index 21bed18c9a..786727bf4e 100644
--- a/src/core/ext/transport/chttp2/transport/bin_decoder.c
+++ b/src/core/ext/transport/chttp2/transport/bin_decoder.c
@@ -133,6 +133,7 @@ bool grpc_base64_decode_partial(struct grpc_base64_decode_context *ctx) {
       switch (input_tail) {
         case 3:
           ctx->output_cur[1] = COMPOSE_OUTPUT_BYTE_1(ctx->input_cur);
+        /* fallthrough */
         case 2:
           ctx->output_cur[0] = COMPOSE_OUTPUT_BYTE_0(ctx->input_cur);
       }
diff --git a/src/core/ext/transport/chttp2/transport/varint.c b/src/core/ext/transport/chttp2/transport/varint.c
index e434ad3c07..ac47fabf22 100644
--- a/src/core/ext/transport/chttp2/transport/varint.c
+++ b/src/core/ext/transport/chttp2/transport/varint.c
@@ -52,12 +52,16 @@ void grpc_chttp2_hpack_write_varint_tail(uint32_t tail_value, uint8_t* target,
   switch (tail_length) {
     case 5:
       target[4] = (uint8_t)((tail_value >> 28) | 0x80);
+    /* fallthrough */
     case 4:
       target[3] = (uint8_t)((tail_value >> 21) | 0x80);
+    /* fallthrough */
     case 3:
       target[2] = (uint8_t)((tail_value >> 14) | 0x80);
+    /* fallthrough */
     case 2:
       target[1] = (uint8_t)((tail_value >> 7) | 0x80);
+    /* fallthrough */
     case 1:
       target[0] = (uint8_t)((tail_value) | 0x80);
   }
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.c b/src/core/ext/transport/cronet/transport/cronet_transport.c
index 67974b0b6a..4f8e0e0603 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.c
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.c
@@ -664,7 +664,7 @@ static void create_grpc_frame(grpc_slice_buffer *write_slice_buffer,
   uint8_t *p = (uint8_t *)write_buffer;
   /* Append 5 byte header */
   /* Compressed flag */
-  *p++ = (flags & GRPC_WRITE_INTERNAL_COMPRESS) ? 1 : 0;
+  *p++ = (uint8_t)((flags & GRPC_WRITE_INTERNAL_COMPRESS) ? 1 : 0);
   /* Message length */
   *p++ = (uint8_t)(length >> 24);
   *p++ = (uint8_t)(length >> 16);
diff --git a/src/core/lib/json/json_reader.c b/src/core/lib/json/json_reader.c
index 5b42ca53ff..75259acc03 100644
--- a/src/core/lib/json/json_reader.c
+++ b/src/core/lib/json/json_reader.c
@@ -192,7 +192,7 @@ grpc_json_reader_status grpc_json_reader_run(grpc_json_reader *reader) {
             if (!success) return GRPC_JSON_PARSE_ERROR;
             json_reader_string_clear(reader);
             reader->state = GRPC_JSON_STATE_VALUE_END;
-          /* The missing break here is intentional. */
+            /* fallthrough */
 
           case GRPC_JSON_STATE_VALUE_END:
           case GRPC_JSON_STATE_OBJECT_KEY_BEGIN:
diff --git a/src/core/lib/support/murmur_hash.c b/src/core/lib/support/murmur_hash.c
index 7137c1f313..921924fee3 100644
--- a/src/core/lib/support/murmur_hash.c
+++ b/src/core/lib/support/murmur_hash.c
@@ -77,8 +77,10 @@ uint32_t gpr_murmur_hash3(const void *key, size_t len, uint32_t seed) {
   switch (len & 3) {
     case 3:
       k1 ^= ((uint32_t)tail[2]) << 16;
+    /* fallthrough */
     case 2:
       k1 ^= ((uint32_t)tail[1]) << 8;
+    /* fallthrough */  
     case 1:
       k1 ^= tail[0];
       k1 *= c1;