diff --git a/tests/tst_spec.c b/tests/tst_spec.c
index 874f2bc9..c3c3cb86 100644
--- a/tests/tst_spec.c
+++ b/tests/tst_spec.c
@@ -8,7 +8,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-#define DATA_LEN 4
+#define DATA_LEN 6
 #define PACKED_LEN 200
 
 /* Prototypes we are testing. */
@@ -17,6 +17,30 @@ int
 main()
 {
     printf("Testing spec functions.\n");
+    {
+        g2int ndpts = DATA_LEN;
+        float fld[DATA_LEN] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0};
+        float fld_in[DATA_LEN];
+        unsigned char cpack[PACKED_LEN];
+        g2int lcpack;
+        g2int idrstmpl[10] = {0, 1, 1, 16, 0, 0, 0, 0, 2, 1};
+        g2int JJ = 1, KK = 1, MM = 1;
+        int i;
+
+        printf("Packing the data...");
+        specpack(fld, ndpts, JJ, KK, MM, idrstmpl, cpack, &lcpack); 
+
+        printf("Unpacking the data...");
+        if (specunpack(cpack, idrstmpl, ndpts, JJ, KK, MM, fld_in))
+            return G2C_ERROR;
+
+        for (i = 0; i < DATA_LEN; i++)
+        {
+            printf("%g %g\n", fld[i], fld_in[i]);
+            if (fld[i] != fld_in[i])
+                return G2C_ERROR;
+        }
+    }
     /* printf("Testing specpack()/specunpack() calls..."); */
     /* { */
     /*     g2int height = 2, width = 2; */
@@ -76,4 +100,4 @@ main()
     /* printf("ok!\n"); */
     printf("SUCCESS!\n");
     return 0;
-}
+}
\ No newline at end of file