diff --git a/iseq.c b/iseq.c
index fffdb79edc..4d7edc550a 100644
--- a/iseq.c
+++ b/iseq.c
@@ -1155,7 +1155,7 @@ iseq_load(VALUE data, const rb_iseq_t *parent, VALUE opt)
         tmp_loc.end_pos.column = NUM2INT(rb_ary_entry(code_location, 3));
     }
 
-    if (RTEST(rb_hash_aref(misc, ID2SYM(rb_intern("prism"))))) {
+    if (SYM2ID(rb_hash_aref(misc, ID2SYM(rb_intern("parser")))) == rb_intern("prism")) {
         ISEQ_BODY(iseq)->prism = true;
     }
 
diff --git a/test/.excludes-prism/TestIseqLoad.rb b/test/.excludes-prism/TestIseqLoad.rb
deleted file mode 100644
index 036e03f7e4..0000000000
--- a/test/.excludes-prism/TestIseqLoad.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-exclude(:test_bug8543, "unknown")
-exclude(:test_case_when, "unknown")
-exclude(:test_hidden, "unknown")
-exclude(:test_kwarg, "unknown")
-exclude(:test_splatsplat, "unknown")