diff --git a/src/wasm/ngx_wasm_ops.c b/src/wasm/ngx_wasm_ops.c
index e7d59153f..a11bc5f70 100644
--- a/src/wasm/ngx_wasm_ops.c
+++ b/src/wasm/ngx_wasm_ops.c
@@ -126,7 +126,7 @@ ngx_wasm_ops_plan_load(ngx_wasm_ops_plan_t *plan, ngx_log_t *log)
     ngx_uint_t               *fid;
     ngx_array_t              *ids;
     ngx_wasm_op_t            *op;
-    ngx_wasm_ops_pipeline_t  *pipeline;
+    ngx_wasm_ops_pipeline_t  *pipeline = NULL;
 
     dd("enter");
 
diff --git a/src/wasm/wrt/ngx_wrt_v8.c b/src/wasm/wrt/ngx_wrt_v8.c
index 55e325292..adc1d3677 100644
--- a/src/wasm/wrt/ngx_wrt_v8.c
+++ b/src/wasm/wrt/ngx_wrt_v8.c
@@ -452,7 +452,9 @@ ngx_v8_init_instance(ngx_wrt_instance_t *instance, ngx_wrt_store_t *store,
     ngx_wrt_module_t *module, ngx_pool_t *pool, ngx_wrt_err_t *err)
 {
     size_t               i;
+#if (NGX_DEBUG)
     ngx_uint_t           nimports = 0;
+#endif
     ngx_wavm_hfunc_t    *import;
     ngx_v8_hfunc_ctx_t  *hctx = NULL;
     wasm_func_t         *func;
@@ -485,7 +487,9 @@ ngx_v8_init_instance(ngx_wrt_instance_t *instance, ngx_wrt_store_t *store,
                                       hctx, NULL);
 
         instance->imports[i] = wasm_func_as_extern(func);
+#if (NGX_DEBUG)
         nimports++;
+#endif
     }
 
     ngx_wasm_assert(nimports == module->nimports);
diff --git a/src/wasm/wrt/ngx_wrt_wasmer.c b/src/wasm/wrt/ngx_wrt_wasmer.c
index 05aed26b3..5bb397555 100644
--- a/src/wasm/wrt/ngx_wrt_wasmer.c
+++ b/src/wasm/wrt/ngx_wrt_wasmer.c
@@ -515,7 +515,9 @@ ngx_wasmer_init_instance(ngx_wrt_instance_t *instance, ngx_wrt_store_t *store,
     ngx_wrt_module_t *module, ngx_pool_t *pool, ngx_wrt_err_t *err)
 {
     size_t                   i, j;
+#if (NGX_DEBUG)
     ngx_uint_t               nimports = 0;
+#endif
     ngx_wrt_import_t        *import;
     ngx_wasmer_hfunc_ctx_t  *hctx, *hctxs = NULL;
     wasm_func_t             *func;
@@ -558,7 +560,9 @@ ngx_wasmer_init_instance(ngx_wrt_instance_t *instance, ngx_wrt_store_t *store,
                     instance->env.data[i] = (wasm_extern_t *)
                         wasmer_named_extern_unwrap(
                             instance->wasi_imports.data[j]);
+#if (NGX_DEBUG)
                     nimports++;
+#endif
                     break;
                 }
             }
@@ -576,7 +580,9 @@ ngx_wasmer_init_instance(ngx_wrt_instance_t *instance, ngx_wrt_store_t *store,
                                           hctx, NULL);
 
             instance->env.data[i] = wasm_func_as_extern(func);
+#if (NGX_DEBUG)
             nimports++;
+#endif
             break;
 
         default: