diff --git a/pub/src/expr.cpp b/pub/src/expr.cpp
index dbe2e58af72917a167323f4b89d6e330175fc222..3136f58766dec783259b127fe04d594fed83178f 100644
--- a/pub/src/expr.cpp
+++ b/pub/src/expr.cpp
@@ -50,11 +50,12 @@ CContext::CContext( uint _k, uint _j, uint _i )
         return;
 
     uint ni = fd->nPts(j);
-    if ( i==(uint)-1 && ni==1 )
-        i = 0;
-    else if ( i>=ni )
+    if ( i==(uint)-1 ) {
+        if ( ni==1 )
+            i = 0;
+    } else if ( i>=ni )
         throw "invalid evaluation context for j="+strg(j)+": i="+
-            strg(i)+">=nJ="+strg(ni);        
+            strg(i)+">=ni="+strg(ni);        
 }
 
 string CContext::context_info() const