diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index daa9ba0..8b5a672 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -226,6 +226,7 @@
 				uint32_t sgsn_ptmsi)
 {
 	uint32_t bss_ptmsi;
+	int max_retries = 23;
 	if (!peer->cfg->patch_ptmsi) {
 		bss_ptmsi = sgsn_ptmsi;
 	} else {
@@ -235,9 +236,12 @@
 
 			if (gbproxy_find_tlli_by_ptmsi(peer, bss_ptmsi))
 				bss_ptmsi = GSM_RESERVED_TMSI;
-		} while (bss_ptmsi == GSM_RESERVED_TMSI);
+		} while (bss_ptmsi == GSM_RESERVED_TMSI && max_retries--);
 	}
 
+	if (bss_ptmsi == GSM_RESERVED_TMSI)
+		LOGP(DGPRS, LOGL_ERROR, "Failed to allocate a BSS P-TMSI\n");
+
 	return bss_ptmsi;
 }
 
@@ -246,6 +250,7 @@
 				uint32_t bss_tlli)
 {
 	uint32_t sgsn_tlli;
+	int max_retries = 23;
 	if (!peer->cfg->patch_ptmsi) {
 		sgsn_tlli = bss_tlli;
 	} else if (tlli_info->sgsn_tlli.ptmsi != GSM_RESERVED_TMSI) {
@@ -259,8 +264,12 @@
 
 			if (gbproxy_find_tlli_by_any_sgsn_tlli(peer, sgsn_tlli))
 				sgsn_tlli = 0;
-		} while (!sgsn_tlli);
+		} while (!sgsn_tlli && max_retries--);
 	}
+
+	if (!sgsn_tlli)
+		LOGP(DGPRS, LOGL_ERROR, "Failed to allocate an SGSN TLLI\n");
+
 	return sgsn_tlli;
 }
 
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index 0c15619..4e51632 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -359,15 +359,23 @@
 {
 	struct sgsn_mm_ctx *mm;
 	uint32_t ptmsi;
+	int max_retries = 23;
 
 restart:
 	ptmsi = rand() | 0xC0000000;
 	llist_for_each_entry(mm, &sgsn_mm_ctxts, list) {
-		if (mm->p_tmsi == ptmsi)
+		if (mm->p_tmsi == ptmsi) {
+			if (!max_retries--)
+				goto failed;
 			goto restart;
+		}
 	}
 
 	return ptmsi;
+
+failed:
+	LOGP(DGPRS, LOGL_ERROR, "Failed to allocate a P-TMSI\n");
+	return GSM_RESERVED_TMSI;
 }
 
 static void drop_one_pdp(struct sgsn_pdp_ctx *pdp)