diff --git a/security/nss/lib/pk11wrap/pk11load.c b/security/nss/lib/pk11wrap/pk11load.c
index f1855058621e..d0d305eb4ddc 100644
--- a/security/nss/lib/pk11wrap/pk11load.c
+++ b/security/nss/lib/pk11wrap/pk11load.c
@@ -336,6 +336,7 @@ SECMOD_LoadPKCS11Module(SECMODModule *mod) {
             mod->isThreadSafe = PR_FALSE;
         }
     }
+    mod->cryptokiVersion = info.cryptokiVersion;
 
     /* If we don't have a common name, get it from the PKCS 11 module */
     if ((mod->commonName == NULL) || (mod->commonName[0] == 0)) {
diff --git a/security/nss/lib/pk11wrap/pk11util.c b/security/nss/lib/pk11wrap/pk11util.c
index 8c017ac86d38..3e1377c581b2 100644
--- a/security/nss/lib/pk11wrap/pk11util.c
+++ b/security/nss/lib/pk11wrap/pk11util.c
@@ -859,7 +859,7 @@ SECMOD_UpdateSlotList(SECMODModule *mod)
 {
     CK_RV crv;
     CK_ULONG count;
-    int i, oldCount;
+    CK_ULONG i, oldCount;
     PRBool freeRef = PR_FALSE;
     void *mark = NULL;
     CK_ULONG *slotIDs = NULL;
@@ -882,7 +882,7 @@ SECMOD_UpdateSlotList(SECMODModule *mod)
  	PZ_Unlock(mod->refLock);
 	return SECSuccess;
     }
-    if (count < mod->slotCount) {
+    if (count < (CK_ULONG)mod->slotCount) {
 	/* shouldn't happen with a properly functioning PKCS #11 module */
 	PORT_SetError( SEC_ERROR_INCOMPATIBLE_PKCS11 );
 	goto loser;
@@ -1060,9 +1060,13 @@ SECMOD_WaitForAnyTokenEvent(SECMODModule *mod, unsigned long flags,
     CK_RV crv;
     PK11SlotInfo *slot;
 
-    if (!pk11_getFinalizeModulesOption()) {
+    if (!pk11_getFinalizeModulesOption() ||
+        ((mod->cryptokiVersion.major == 2) &&
+         (mod->cryptokiVersion.minor < 1))) { 
         /* if we are sharing the module with other software in our
-         * address space, we can't reliably use C_WaitForSlotEvent() */
+         * address space, we can't reliably use C_WaitForSlotEvent(),
+         * and if the module is version 2.0, C_WaitForSlotEvent() doesn't
+         * exist */
 	return secmod_HandleWaitForSlotEvent(mod, flags, latency);
     }
     /* first the the PKCS #11 call */
diff --git a/security/nss/lib/pk11wrap/secmodt.h b/security/nss/lib/pk11wrap/secmodt.h
index 73d14f726d8f..9114ce1f8e5b 100644
--- a/security/nss/lib/pk11wrap/secmodt.h
+++ b/security/nss/lib/pk11wrap/secmodt.h
@@ -40,6 +40,7 @@
 #include "nssilckt.h"
 #include "secoid.h"
 #include "secasn1.h"
+#include "pkcs11t.h"
 
 /* find a better home for these... */
 extern const SEC_ASN1Template SECKEY_PointerToEncryptedPrivateKeyInfoTemplate[];
@@ -97,6 +98,7 @@ struct SECMODModuleStr {
     int		cipherOrder;	/* order for cipher operations */
     unsigned long evControlMask; /* control the running and shutdown of slot
 				  * events (SECMOD_WaitForAnyTokenEvent) */
+    CK_VERSION  cryptokiVersion; /* version of this library */
 };
 
 /* evControlMask flags */