diff --git a/core/shared/platform/baremetal/platform_init.c b/core/shared/platform/baremetal/platform_init.c
index a617f94d..b986c21b 100644
--- a/core/shared/platform/baremetal/platform_init.c
+++ b/core/shared/platform/baremetal/platform_init.c
@@ -591,9 +591,9 @@ strcspn(const char *s, const char *c)
 }
 
 __attribute__((weak)) int
-isupper(int c)
+isupper(int d)
 {
-    return (unsigned)c - 'A' < 26;
+    return (unsigned)d - 'A' < 26;
 }
 
 __attribute__((weak)) int