diff --git a/arch/s390/include/asm/cpacf.h b/arch/s390/include/asm/cpacf.h
index fa31f71cf574..0f6ff2008a15 100644
--- a/arch/s390/include/asm/cpacf.h
+++ b/arch/s390/include/asm/cpacf.h
@@ -161,6 +161,13 @@
 
 typedef struct { unsigned char bytes[16]; } cpacf_mask_t;
 
+/*
+ * Prototype for a not existing function to produce a link
+ * error if __cpacf_query() or __cpacf_check_opcode() is used
+ * with an invalid compile time const opcode.
+ */
+void __cpacf_bad_opcode(void);
+
 static __always_inline void __cpacf_query_rre(u32 opc, u8 r1, u8 r2,
 					      cpacf_mask_t *mask)
 {
@@ -232,7 +239,7 @@ static __always_inline void __cpacf_query(unsigned int opcode,
 		__cpacf_query_rre(CPACF_PRNO, 2, 4, mask);
 		break;
 	default:
-		BUG();
+		__cpacf_bad_opcode();
 	}
 }
 
@@ -257,7 +264,8 @@ static __always_inline int __cpacf_check_opcode(unsigned int opcode)
 	case CPACF_KMA:
 		return test_facility(146);	/* check for MSA8 */
 	default:
-		BUG();
+		__cpacf_bad_opcode();
+		return 0;
 	}
 }