diff --git a/include/mimalloc/prim.h b/include/mimalloc/prim.h
index 830b36c4..1a6adcc7 100644
--- a/include/mimalloc/prim.h
+++ b/include/mimalloc/prim.h
@@ -287,7 +287,7 @@ static inline mi_heap_t* mi_prim_get_default_heap(void);
 
 #if defined(MI_TLS_SLOT)
 # if !defined(MI_HAS_TLS_SLOT)
-#  error "trying to use a TLS slot for the default heap, but the mi_prim_tls_slot primitives are not defined
+#  error "trying to use a TLS slot for the default heap, but the mi_prim_tls_slot primitives are not defined"
 # endif
 
 static inline mi_heap_t* mi_prim_get_default_heap(void) {