diff --git a/sys/arm64/include/db_machdep.h b/sys/arm64/include/db_machdep.h
--- a/sys/arm64/include/db_machdep.h
+++ b/sys/arm64/include/db_machdep.h
@@ -97,7 +97,7 @@
 				  (((ins) & 0xffe00c00u) != 0x3c800000u)) ||  /* unscaled immediate */ \
 				 ((((ins) & 0x3b000000u) == 0x39000000u) && \
 				  (((ins) & 0x3bc00000u) != 0x39000000u) && \
-				  (((ins) & 0xffc00000u) != 0x3d800000u)) &&  /* unsigned immediate */ \
+				  (((ins) & 0xffc00000u) != 0x3d800000u)) ||  /* unsigned immediate */ \
 				 (((ins) & 0x3bc00000u) == 0x28400000u) || /* pair (offset) */ \
 				 (((ins) & 0x3bc00000u) == 0x28c00000u) || /* pair (post-indexed) */ \
 				 (((ins) & 0x3bc00000u) == 0x29800000u)) /* pair (pre-indexed) */