diff --git a/etc/opensc.conf.example b/etc/opensc.conf.example
index 9ff6b421..e07a77c0 100644
--- a/etc/opensc.conf.example
+++ b/etc/opensc.conf.example
@@ -141,3 +141,19 @@ app scam {
 		use_caching = false;
 	}
 }
+
+# Parameters for the OpenSC PKCS11 module
+app opensc-pkcs11 {
+	pkcs11 {
+		# Maxmimum number of slots per smart card.
+		# If the card has fewer keys than defined here,
+		# the remaining number of slots will be empty.
+		# Setting this value to 0 will cause the pkcs11
+		# module to allocate just as many slots as needed.
+		#
+		# Note that there is currently a compile time
+		# maximum on the overall number of slots
+		# the pkcs11 module is able to handle.
+		num_slots = 4;
+	}
+}
diff --git a/src/pkcs11/framework-pkcs15.c b/src/pkcs11/framework-pkcs15.c
index 5db10c5e..0cb05597 100644
--- a/src/pkcs11/framework-pkcs15.c
+++ b/src/pkcs11/framework-pkcs15.c
@@ -389,9 +389,11 @@ static CK_RV pkcs15_create_tokens(struct sc_pkcs11_card *p11card)
 	}
 
 	/* Create read/write slots */
-	while (slot_allocate(&slot, p11card) == CKR_OK) {
-		pkcs15_init_token_info(card, &slot->token_info);
-		slot->token_info.flags = CKF_TOKEN_INITIALIZED;
+	if (sc_pkcs11_conf.num_slots != 0) {
+		while (slot_allocate(&slot, p11card) == CKR_OK) {
+			pkcs15_init_token_info(card, &slot->token_info);
+			slot->token_info.flags = CKF_TOKEN_INITIALIZED;
+		}
 	}
 
 	debug(context, "All tokens created\n");
diff --git a/src/pkcs11/misc.c b/src/pkcs11/misc.c
index 746f2de9..8057ddc5 100644
--- a/src/pkcs11/misc.c
+++ b/src/pkcs11/misc.c
@@ -297,3 +297,25 @@ CK_RV attr_find_var(CK_ATTRIBUTE_PTR pTemplate, CK_ULONG ulCount,
 	return attr_extract(pTemplate, ptr, sizep);
 }
 
+void load_pkcs11_parameters(struct sc_pkcs11_config *conf, struct sc_context *ctx)
+{
+	scconf_block *conf_block = NULL, **blocks;
+	int i;
+	
+	/* Set defaults */
+	conf->num_slots = SC_PKCS11_MAX_VIRTUAL_SLOTS;
+
+	for (i = 0; ctx->conf_blocks[i] != NULL; i++) {
+		blocks = scconf_find_blocks(ctx->conf, ctx->conf_blocks[i],
+				"pkcs11", NULL);
+		conf_block = blocks[0];
+		free(blocks);
+		if (conf_block != NULL)
+			break;
+	}
+
+	if (!conf_block)
+		return;
+
+	conf->num_slots = scconf_get_int(conf_block, "num_slots", conf->num_slots);
+}
diff --git a/src/pkcs11/pkcs11-global.c b/src/pkcs11/pkcs11-global.c
index ca3dcbe9..5e6dcaf0 100644
--- a/src/pkcs11/pkcs11-global.c
+++ b/src/pkcs11/pkcs11-global.c
@@ -26,6 +26,7 @@ struct sc_context *context = NULL;
 struct sc_pkcs11_pool session_pool;
 struct sc_pkcs11_slot virtual_slots[SC_PKCS11_MAX_VIRTUAL_SLOTS];
 struct sc_pkcs11_card card_table[SC_PKCS11_MAX_READERS];
+struct sc_pkcs11_config sc_pkcs11_conf;
 
 extern CK_FUNCTION_LIST pkcs11_function_list;
 
@@ -41,6 +42,9 @@ CK_RV C_Initialize(CK_VOID_PTR pReserved)
 	if (rc != 0)
 		return CKR_DEVICE_ERROR;
 
+	/* Load configuration */
+	load_pkcs11_parameters(&sc_pkcs11_conf, context);
+
         pool_initialize(&session_pool, POOL_TYPE_SESSION);
 	for (i=0; i<SC_PKCS11_MAX_VIRTUAL_SLOTS; i++)
                 slot_initialize(i, &virtual_slots[i]);
diff --git a/src/pkcs11/sc-pkcs11.h b/src/pkcs11/sc-pkcs11.h
index 949dce9c..52982466 100644
--- a/src/pkcs11/sc-pkcs11.h
+++ b/src/pkcs11/sc-pkcs11.h
@@ -50,7 +50,7 @@
 extern "C" {
 #endif
 
-#define SC_PKCS11_MAX_VIRTUAL_SLOTS	4
+#define SC_PKCS11_MAX_VIRTUAL_SLOTS	8
 #define SC_PKCS11_MAX_READERS           2
 
 struct sc_pkcs11_session;
@@ -78,6 +78,9 @@ struct sc_pkcs11_pool {
         struct sc_pkcs11_pool_item *tail;
 };
 
+struct sc_pkcs11_config {
+	unsigned int num_slots;
+};
 
 /*
  * PKCS#11 Object abstraction layer
@@ -160,6 +163,10 @@ struct sc_pkcs11_card {
         struct sc_pkcs11_framework_ops *framework;
 	void *fw_data;
 
+	/* Number of slots owned by this card object */
+	unsigned int num_slots;
+	unsigned int max_slots;
+
 	/* List of supported mechanisms */
 	struct sc_pkcs11_mechanism_type **mechanisms;
 	unsigned int nmechanisms;
@@ -261,6 +268,7 @@ extern struct sc_context *context;
 extern struct sc_pkcs11_pool session_pool;
 extern struct sc_pkcs11_slot virtual_slots[SC_PKCS11_MAX_VIRTUAL_SLOTS];
 extern struct sc_pkcs11_card card_table[SC_PKCS11_MAX_READERS];
+extern struct sc_pkcs11_config sc_pkcs11_conf;
 
 /* Framework definitions */
 extern struct sc_pkcs11_framework_ops framework_pkcs15;
@@ -341,6 +349,9 @@ CK_RV sc_pkcs11_register_sign_and_hash_mechanism(struct sc_pkcs11_card *,
 				CK_MECHANISM_TYPE, CK_MECHANISM_TYPE,
 				sc_pkcs11_mechanism_type_t *);
 
+/* Load configuration defaults */
+void load_pkcs11_parameters(struct sc_pkcs11_config *, struct sc_context *);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/pkcs11/slot.c b/src/pkcs11/slot.c
index b8caf6ed..3c7dad58 100644
--- a/src/pkcs11/slot.c
+++ b/src/pkcs11/slot.c
@@ -78,6 +78,13 @@ CK_RV card_detect(int reader)
 		debug(context, "%d: Detecting Framework\n", reader);
 
 		card = &card_table[reader];
+
+		if (sc_pkcs11_conf.num_slots == 0)
+			card->max_slots = SC_PKCS11_MAX_VIRTUAL_SLOTS;
+		else
+			card->max_slots = sc_pkcs11_conf.num_slots;
+		card->num_slots = 0;
+
 		for (i = 0; frameworks[i]; i++) {
 			if (frameworks[i]->bind == NULL)
 				continue;
@@ -142,6 +149,10 @@ CK_RV slot_initialize(int id, struct sc_pkcs11_slot *slot)
 CK_RV slot_allocate(struct sc_pkcs11_slot **slot, struct sc_pkcs11_card *card)
 {
         int i;
+
+	if (card->num_slots >= card->max_slots)
+		return CKR_FUNCTION_FAILED;
+
 	for (i=0; i<SC_PKCS11_MAX_VIRTUAL_SLOTS; i++) {
 		if (!(virtual_slots[i].slot_info.flags & CKF_TOKEN_PRESENT)) {
 			debug(context, "Allocated slot %d\n", i);
@@ -149,7 +160,8 @@ CK_RV slot_allocate(struct sc_pkcs11_slot **slot, struct sc_pkcs11_card *card)
                         virtual_slots[i].slot_info.flags |= CKF_TOKEN_PRESENT;
                         virtual_slots[i].card = card;
 			*slot = &virtual_slots[i];
-                        return CKR_OK;
+			card->num_slots++;
+			return CKR_OK;
 		}
 	}
         return CKR_FUNCTION_FAILED;