diff --git a/security/nss/lib/base/base.h b/security/nss/lib/base/base.h
index 0970c3fed49..f57710b6975 100644
--- a/security/nss/lib/base/base.h
+++ b/security/nss/lib/base/base.h
@@ -35,7 +35,7 @@
 #define BASE_H
 
 #ifdef DEBUG
-static const char BASE_CVS_ID[] = "@(#) $RCSfile: base.h,v $ $Revision: 1.10 $ $Date: 2001-11-28 16:23:34 $ $Name:  $";
+static const char BASE_CVS_ID[] = "@(#) $RCSfile: base.h,v $ $Revision: 1.11 $ $Date: 2001-12-12 20:23:05 $ $Name:  $";
 #endif /* DEBUG */
 
 /*
@@ -1055,6 +1055,9 @@ nssHash_Destroy
  * nssHash_Add
  *
  */
+
+extern const NSSError NSS_ERROR_HASH_COLLISION;
+
 NSS_EXTERN PRStatus
 nssHash_Add
 (
diff --git a/security/nss/lib/base/errorval.c b/security/nss/lib/base/errorval.c
index b243b04fdf8..816d8506429 100644
--- a/security/nss/lib/base/errorval.c
+++ b/security/nss/lib/base/errorval.c
@@ -32,7 +32,7 @@
  */
 
 #ifdef DEBUG
-static const char CVS_ID[] = "@(#) $RCSfile: errorval.c,v $ $Revision: 1.5 $ $Date: 2001-12-10 19:14:32 $ $Name:  $";
+static const char CVS_ID[] = "@(#) $RCSfile: errorval.c,v $ $Revision: 1.6 $ $Date: 2001-12-12 20:23:06 $ $Name:  $";
 #endif /* DEBUG */
 
 /*
@@ -85,3 +85,5 @@ const NSSError NSS_ERROR_CERTIFICATE_ISSUER_NOT_FOUND   = 31;
 
 const NSSError NSS_ERROR_CERTIFICATE_IN_CACHE           = 32;
 
+const NSSError NSS_ERROR_HASH_COLLISION                 = 33;
+
diff --git a/security/nss/lib/base/hash.c b/security/nss/lib/base/hash.c
index 897d28382c6..1a34507feac 100644
--- a/security/nss/lib/base/hash.c
+++ b/security/nss/lib/base/hash.c
@@ -32,7 +32,7 @@
  */
 
 #ifdef DEBUG
-static const char CVS_ID[] = "@(#) $RCSfile: hash.c,v $ $Revision: 1.5 $ $Date: 2001-11-29 19:33:59 $ $Name:  $";
+static const char CVS_ID[] = "@(#) $RCSfile: hash.c,v $ $Revision: 1.6 $ $Date: 2001-12-12 20:23:07 $ $Name:  $";
 #endif /* DEBUG */
 
 /*
@@ -246,7 +246,7 @@ nssHash_Add
   const void *value
 )
 {
-  PRStatus error = PR_SUCCESS;
+  PRStatus error = PR_FAILURE;
   PLHashEntry *he;
 
   PZ_Lock(hash->mutex);
@@ -254,8 +254,11 @@ nssHash_Add
   he = PL_HashTableAdd(hash->plHashTable, key, (void *)value);
   if( (PLHashEntry *)NULL == he ) {
     nss_SetError(NSS_ERROR_NO_MEMORY);
+  } else if (he->value != value) {
+    nss_SetError(NSS_ERROR_HASH_COLLISION);
   } else {
     hash->count++;
+    error = PR_SUCCESS;
   }
 
   (void)PZ_Unlock(hash->mutex);