diff --git a/src/asahi/compiler/agx_validate.c b/src/asahi/compiler/agx_validate.c
index ff6bbb8d6c7..ae17f7f9a0e 100644
--- a/src/asahi/compiler/agx_validate.c
+++ b/src/asahi/compiler/agx_validate.c
@@ -96,6 +96,8 @@ agx_validate_sources(agx_instr *I)
           */
          agx_validate_assert(src.size == AGX_SIZE_16);
          agx_validate_assert(src.value < (1 << (ldst ? 16 : 8)));
+      } else if (I->op == AGX_OPCODE_COLLECT && !agx_is_null(src)) {
+         agx_validate_assert(src.size == I->src[0].size);
       }
    }