--- a/src/g23m-aci/aci/cmh_ccs.c	Tue Oct 11 03:19:56 2016 +0000
+++ b/src/g23m-aci/aci/cmh_ccs.c	Tue Oct 11 03:43:18 2016 +0000
@@ -1079,10 +1079,20 @@
   }
 #endif /* FAX_AND_DATA */
 
-/* 
+  /* 
    * 3GPP standard 27007 
    * (+CVHU)
+   *
+   * FreeCalypso note: +CVHU support was not present in the TCS211 version
+   * of ACI, but it appears in the version we got from the LoCosto source.
+   * The following stanza is a new addition with this LoCosto version,
+   * and it was broken for our sans-PSI configuration: the reference to
+   * to psiShrdPrm only works when PSI is there, and it is a compilation
+   * failure otherwise.  The conditional on FF_PSI and the #else version
+   * have been added by Space Falcon; the correctness of the latter is
+   * not yet known.
    */
+#ifdef FF_PSI
   if( ccShrdPrm.cvhu EQ CVHU_DropDTR_ATH_IGNORED OR
     ((psiShrdPrm.dtr_clearcall EQ TRUE) AND 
      (ccShrdPrm.cvhu EQ CVHU_DropDTR_IGNORED)) )
@@ -1090,6 +1100,11 @@
     psiShrdPrm.dtr_clearcall = FALSE;  
     return (AT_CMPL);
   }
+#else
+  if( ccShrdPrm.cvhu EQ CVHU_DropDTR_ATH_IGNORED )
+    return (AT_CMPL);
+#endif
+
 /*
  *-------------------------------------------------------------------
  * check for a call with CCBS possible