diff --git a/testament/categories.nim b/testament/categories.nim
index e8b13746a1..cae6993276 100644
--- a/testament/categories.nim
+++ b/testament/categories.nim
@@ -718,6 +718,8 @@ proc processCategory(r: var TResults, cat: Category,
     case cat2
     of "megatest":
       runJoinedTest(r, cat, testsDir, options)
+      if isNimRepoTests():
+        runJoinedTest(r, cat, testsDir, options & " --mm:refc")
     else:
       var testsRun = 0
       var files: seq[string]
diff --git a/tests/enum/tenum.nim b/tests/enum/tenum.nim
index b11b02ec68..88d85ddcc4 100644
--- a/tests/enum/tenum.nim
+++ b/tests/enum/tenum.nim
@@ -174,4 +174,5 @@ block: # bug #12589
     proc typ(): OGRwkbGeometryType =
       return wkbPoint25D
 
-    doAssert $typ() == "wkbPoint25D"
+    when not defined(gcRefc):
+      doAssert $typ() == "wkbPoint25D"
diff --git a/tests/misc/t18079.nim b/tests/misc/t18079.nim
index 352348daf9..ae64bbff92 100644
--- a/tests/misc/t18079.nim
+++ b/tests/misc/t18079.nim
@@ -1,3 +1,7 @@
+discard """
+  matrix: "--mm:orc"
+"""
+
 type
   Foo = object
     y: int
diff --git a/tests/misc/tunsignedconv.nim b/tests/misc/tunsignedconv.nim
index 989f39277a..c32f85b4dc 100644
--- a/tests/misc/tunsignedconv.nim
+++ b/tests/misc/tunsignedconv.nim
@@ -66,7 +66,8 @@ let limit = 1'u64
 
 let rangeVar = 0'u64 ..< limit
 
-doAssert repr(rangeVar) == """0 .. 0""", repr(rangeVar)
+when not defined(gcRefc):
+  doAssert repr(rangeVar) == """0 .. 0""", repr(rangeVar)
 
 # bug #15210
 
diff --git a/tests/typerel/ttypedesc_as_genericparam1_orc.nim b/tests/typerel/ttypedesc_as_genericparam1_orc.nim
index 0ee4d8f925..d528a74219 100644
--- a/tests/typerel/ttypedesc_as_genericparam1_orc.nim
+++ b/tests/typerel/ttypedesc_as_genericparam1_orc.nim
@@ -1 +1,5 @@
-doAssert repr(int) == "int"
\ No newline at end of file
+discard """
+  matrix: "--mm:orc"
+"""
+
+doAssert repr(int) == "int"