diff --git a/base/mf_existvar.sas b/base/mf_existvar.sas
index 90cd34d..4ca518d 100755
--- a/base/mf_existvar.sas
+++ b/base/mf_existvar.sas
@@ -7,8 +7,12 @@
 
         %put %mf_existvar(work.someds, somevar)
 
-  @param libds (positional) - 2 part dataset or view reference
-  @param var (positional) - variable name
+  @param [in] libds 2 part dataset or view reference
+  @param [in] var variable name
+
+  <h4> Related Macros </h4>
+  @li mf_existvar.test.sas
+
   @version 9.2
   @author Allan Bowe
 **/
diff --git a/base/mp_makedata.sas b/base/mp_makedata.sas
index 0b583d3..eb7e98a 100644
--- a/base/mp_makedata.sas
+++ b/base/mp_makedata.sas
@@ -92,6 +92,7 @@ data &ds2;
     %end;
     output;
   end;
+  stop;
 run;
 proc sort data=&ds2 nodupkey;
   by &pk_fields;
diff --git a/tests/crossplatform/mf_existvar.test.sas b/tests/crossplatform/mf_existvar.test.sas
new file mode 100644
index 0000000..efb6ca9
--- /dev/null
+++ b/tests/crossplatform/mf_existvar.test.sas
@@ -0,0 +1,22 @@
+/**
+  @file
+  @brief Testing mf_existvar macro
+
+  <h4> SAS Macros </h4>
+  @li mf_existvar.sas
+  @li mp_assert.sas
+
+**/
+
+
+%mp_assert(
+  iftrue=(%mf_existvar(sashelp.class,age)=1),
+  desc=Checking existing var exists,
+  outds=work.test_results
+)
+
+%mp_assert(
+  iftrue=(%mf_existvar(sashelp.class,isjustanumber)=0),
+  desc=Checking non existing var does not exist,
+  outds=work.test_results
+)
\ No newline at end of file