diff --git a/openbsc/src/gprs/sgsn_libgtp.c b/openbsc/src/gprs/sgsn_libgtp.c
index a19af36..7c17f9d 100644
--- a/openbsc/src/gprs/sgsn_libgtp.c
+++ b/openbsc/src/gprs/sgsn_libgtp.c
@@ -317,6 +317,10 @@
 	/* Confirm deactivation of PDP context to MS */
 	rc = gsm48_tx_gsm_deact_pdp_acc(pctx);
 
+	/* unlink the now non-existing library handle from the pdp
+	 * context */
+	pctx->lib = NULL;
+
 	sgsn_pdp_ctx_free(pctx);
 
 	return rc;
@@ -422,10 +426,16 @@
 
 	pdp = lib->priv;
 	if (!pdp) {
-		DEBUGP(DGPRS, "GTP DATA IND from GGSN for unknown PDP\n");
+		LOGP(DGPRS, LOGL_NOTICE,
+		     "GTP DATA IND from GGSN for unknown PDP\n");
 		return -EIO;
 	}
 	mm = pdp->mm;
+	if (!mm) {
+		LOGP(DGPRS, LOGL_ERROR,
+		     "PDP context (imsi=%s) without MM context!\n", mm->imsi);
+		return -EIO;
+	}
 
 	msg = msgb_alloc_headroom(len+256, 128, "GTP->SNDCP");
 	ud = msgb_put(msg, len);