diff --git a/sys/dev/random/fenestrasX/fx_pool.c b/sys/dev/random/fenestrasX/fx_pool.c
--- a/sys/dev/random/fenestrasX/fx_pool.c
+++ b/sys/dev/random/fenestrasX/fx_pool.c
@@ -127,7 +127,7 @@
  */
 static const struct fxrng_ent_char {
 	const struct fxrng_ent_cls	*entc_cls;
-} fxrng_ent_char[ENTROPYSOURCE] = {
+} fxrng_ent_char[/*ENTROPYSOURCE*/] = {
 	[RANDOM_CACHED] = {
 		.entc_cls = &fxrng_hi_push,
 	},
@@ -216,6 +216,8 @@
 		.entc_cls = &fxrng_hi_pull,
 	},
 };
+CTASSERT(nitems(fxrng_ent_char) == ENTROPYSOURCE);
+CTASSERT(ENTROPYSOURCE <= sizeof(hc_source_mask) * NBBY);
 
 /* Useful for single-bit-per-source state. */
 BITSET_DEFINE(fxrng_bits, ENTROPYSOURCE);
diff --git a/sys/dev/random/random_harvestq.c b/sys/dev/random/random_harvestq.c
--- a/sys/dev/random/random_harvestq.c
+++ b/sys/dev/random/random_harvestq.c
@@ -88,7 +88,7 @@
 static __read_mostly bool epoch_inited;
 static __read_mostly epoch_t rs_epoch;
 
-static const char *random_source_descr[ENTROPYSOURCE];
+static const char *random_source_descr[];
 
 /*
  * How many events to queue up. We create this many items in
@@ -647,7 +647,7 @@
     random_print_harvestmask, "A",
     "Entropy harvesting mask (printable)");
 
-static const char *random_source_descr[ENTROPYSOURCE] = {
+static const char *random_source_descr[/*ENTROPYSOURCE*/] = {
 	[RANDOM_CACHED] = "CACHED",
 	[RANDOM_ATTACH] = "ATTACH",
 	[RANDOM_KEYBOARD] = "KEYBOARD",
@@ -679,6 +679,8 @@
 	[RANDOM_PURE_ARM_TRNG] = "PURE_ARM_TRNG",
 	/* "ENTROPYSOURCE" */
 };
+CTASSERT(nitems(random_source_descr) == ENTROPYSOURCE);
+CTASSERT(ENTROPYSOURCE <= sizeof(hc_source_mask) * NBBY);
 
 static int
 random_print_harvestmask_symbolic(SYSCTL_HANDLER_ARGS)