diff --git a/mace/core/runtime/cpu/cpu_runtime.h b/mace/core/runtime/cpu/cpu_runtime.h
index bb97267f67f46f1bb47b1729d162985b055418f7..ab067ebaae698e2296dcee5469c93961f654b628 100644
--- a/mace/core/runtime/cpu/cpu_runtime.h
+++ b/mace/core/runtime/cpu/cpu_runtime.h
@@ -52,13 +52,13 @@ class CPURuntime {
 
 #ifdef MACE_ENABLE_QUANTIZE
   ~CPURuntime() {
-    if (!gemm_context_) {
+    if (gemm_context_ != nullptr) {
       delete static_cast<gemmlowp::GemmContext*>(gemm_context_);
     }
   }
 
   gemmlowp::GemmContext *GetGemmlowpContext() {
-    if (!gemm_context_) {
+    if (gemm_context_ == nullptr) {
       gemm_context_ = new gemmlowp::GemmContext();
     }
     return static_cast<gemmlowp::GemmContext*>(gemm_context_);