diff --git a/include/jemalloc/internal/util.h b/include/jemalloc/internal/util.h
index 84796936..969e3e39 100644
--- a/include/jemalloc/internal/util.h
+++ b/include/jemalloc/internal/util.h
@@ -42,12 +42,6 @@
 } while (0)
 #endif
 
-/* Use to assert a particular configuration, e.g., cassert(config_debug). */
-#define	cassert(c) do {							\
-	if ((c) == false)						\
-		assert(false);						\
-} while (0)
-
 #ifndef not_reached
 #define	not_reached() do {						\
 	if (config_debug) {						\
@@ -74,6 +68,12 @@
 		not_implemented();					\
 } while (0)
 
+/* Use to assert a particular configuration, e.g., cassert(config_debug). */
+#define	cassert(c) do {							\
+	if ((c) == false)						\
+		not_reached();						\
+} while (0)
+
 #endif /* JEMALLOC_H_TYPES */
 /******************************************************************************/
 #ifdef JEMALLOC_H_STRUCTS
diff --git a/src/jemalloc.c b/src/jemalloc.c
index ae56db6b..5cbfc3f6 100644
--- a/src/jemalloc.c
+++ b/src/jemalloc.c
@@ -484,8 +484,7 @@ malloc_conf_init(void)
 			}
 			break;
 		} default:
-			/* NOTREACHED */
-			assert(false);
+			not_reached();
 			buf[0] = '\0';
 			opts = buf;
 		}
diff --git a/src/prof.c b/src/prof.c
index c133b95c..4a12d1f9 100644
--- a/src/prof.c
+++ b/src/prof.c
@@ -423,7 +423,7 @@ prof_backtrace(prof_bt_t *bt, unsigned nignore)
 {
 
 	cassert(config_prof);
-	assert(false);
+	not_reached();
 }
 #endif
 
@@ -511,7 +511,7 @@ prof_lookup(prof_bt_t *bt)
 			assert(ret.v != NULL);
 			if (ckh_remove(&prof_tdata->bt2cnt, ret.p->ctx->bt,
 			    NULL, NULL))
-				assert(false);
+				not_reached();
 			ql_remove(&prof_tdata->lru_ql, ret.p, lru_link);
 			prof_ctx_merge(ret.p->ctx, ret.p);
 			/* ret can now be re-used. */
@@ -695,7 +695,7 @@ prof_ctx_destroy(prof_ctx_t *ctx)
 		assert(ctx->cnt_merged.accumbytes == 0);
 		/* Remove ctx from bt2ctx. */
 		if (ckh_remove(&bt2ctx, ctx->bt, NULL, NULL))
-			assert(false);
+			not_reached();
 		prof_leave(prof_tdata);
 		/* Destroy ctx. */
 		malloc_mutex_unlock(ctx->lock);
diff --git a/src/util.c b/src/util.c
index b3a01143..679fa763 100644
--- a/src/util.c
+++ b/src/util.c
@@ -554,7 +554,7 @@ malloc_vsnprintf(char *str, size_t size, const char *format, va_list ap)
 				f++;
 				break;
 			}
-			default: not_implemented();
+			default: not_reached();
 			}
 			break;
 		} default: {
diff --git a/src/zone.c b/src/zone.c
index c62c183f..e0302ef4 100644
--- a/src/zone.c
+++ b/src/zone.c
@@ -137,7 +137,7 @@ zone_destroy(malloc_zone_t *zone)
 {
 
 	/* This function should never be called. */
-	assert(false);
+	not_reached();
 	return (NULL);
 }