diff --git a/src/info.c b/src/info.c
index 45a4c88d9..12dd61a84 100644
--- a/src/info.c
+++ b/src/info.c
@@ -4285,7 +4285,7 @@ mobjinfo_t mobjinfo[NUMMOBJTYPES] =
 		S_DETON1,       // spawnstate
 		1,              // spawnhealth
 		S_DETON2,       // seestate
-		sfx_None,       // seesound
+		sfx_s3k86,      // seesound -- sfx_kc57 for a self-propelled deton...
 		1,              // reactiontime
 		sfx_deton,      // attacksound
 		S_NULL,         // painstate
diff --git a/src/sounds.c b/src/sounds.c
index 596ed74f2..48f929b73 100644
--- a/src/sounds.c
+++ b/src/sounds.c
@@ -528,7 +528,7 @@ sfxinfo_t S_sfx[NUMSFX] =
   {"s3k83",  false,  64,  0, -1, NULL, 0,        -1,  -1, LUMPERROR, "Collapsing"},
   {"s3k84",  false,  64,  0, -1, NULL, 0,        -1,  -1, LUMPERROR, "Powering up"},
   {"s3k85",  false,  64,  0, -1, NULL, 0,        -1,  -1, LUMPERROR, "Powering down"},
-  {"s3k86",  false,  64,  0, -1, NULL, 0,        -1,  -1, LUMPERROR, "Alarm"},
+  {"s3k86",  false, 128,  8, -1, NULL, 0,        -1,  -1, LUMPERROR, "Alarm"},
   {"s3k87",  false,  64,  0, -1, NULL, 0,        -1,  -1, LUMPERROR, "Bounce"},
   {"s3k88",  false,  64,  0, -1, NULL, 0,        -1,  -1, LUMPERROR, "Metallic squeak"},
   {"s3k89",  false,  64,  0, -1, NULL, 0,        -1,  -1, LUMPERROR, "Advanced tech"},