diff --git a/tests/include/tast2.h b/tests/include/tast2.h
index 42c852f..b47a801 100644
--- a/tests/include/tast2.h
+++ b/tests/include/tast2.h
@@ -34,6 +34,8 @@ extern "C" {
 #define EQ6 AVAL == BVAL
 
 #define SIZEOF sizeof(char)
+#define REG_STR "regular string"
+#define NOTSUPPORTEDSTR "not a " REG_STR
 
 #define NULLCHAR '\0'/* comments should not break things*/
 #define OCTCHAR '\012' // nor should this comment
diff --git a/tests/tast2.nim b/tests/tast2.nim
index da7fafa..4cfbeac 100644
--- a/tests/tast2.nim
+++ b/tests/tast2.nim
@@ -109,6 +109,8 @@ assert C == 0x10
 assert D == "hello"
 assert E == 'c'
 
+assert not defined(NOTSUPPORTEDSTR)
+
 assert UEXPR == (1234.uint shl 1)
 assert ULEXPR == (1234.uint32 shl 2)
 assert ULLEXPR == (1234.uint64 shl 3)