diff --git a/src/frontend/outitf.c b/src/frontend/outitf.c
index 2c5e190de..7b6671bee 100644
--- a/src/frontend/outitf.c
+++ b/src/frontend/outitf.c
@@ -469,9 +469,9 @@ addSpecialDesc(runDesc *run, char *name, char *devname, char *param, int depind)
 static void
 OUTpD_memory(runDesc *run, IFvalue *refValue, IFvalue *valuePtr)
 {
-    int i;
+    int i, n = run->numData;
 
-    for (i = 0; i < run->numData; i++) {
+    for (i = 0; i < n; i++) {
 
 #ifdef TCL_MODULE
         /*Locks the blt vector to stop access*/