diff --git a/source/interfaces/retro-unix.c b/source/interfaces/retro-unix.c
index 777c5db..74b3e53 100644
--- a/source/interfaces/retro-unix.c
+++ b/source/interfaces/retro-unix.c
@@ -308,6 +308,11 @@ void rre_execute(CELL cell, int silent) {
       printf("At %d, opcode %d\n", ip, opcode);
       exit(1);
     }
+    if (rp < 0 || rp > ADDRESSES) {
+      printf("\nERROR (nga/rre_execute): Address Stack Limits Exceeded!\n");
+      printf("At %d, opcode %d\n", ip, opcode);
+      exit(1);
+    }
 #endif
     ip++;
     if (rp == 0)
diff --git a/source/retro.forth b/source/retro.forth
index 7c98b91..19418b7 100644
--- a/source/retro.forth
+++ b/source/retro.forth
@@ -412,7 +412,7 @@ Apply q to x, y, and z.
 Execute quote until quote returns a flag of 0. In high level code:
 
   :while  (q-)
-    [ repeat dup dup push call swap 0; drop again ] call drop ;
+    [ repeat dup push call pop swap 0; drop again ] call drop ;
 
 This is manually translated to assembly and inlined for performance.