diff --git a/php_memcached.c b/php_memcached.c
index c1bce93b..ac40092a 100644
--- a/php_memcached.c
+++ b/php_memcached.c
@@ -576,7 +576,7 @@ static void php_memc_get_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 	MEMC_METHOD_FETCH_OBJECT;
 	i_obj->rescode = MEMCACHED_SUCCESS;
 
-	if (key_len == 0 || strchr(key, ' ')) {
+	if (key_len == 0 || (!memcached_behavior_get(m_obj->memc, MEMCACHED_BEHAVIOR_BINARY_PROTOCOL) && strchr(key, ' '))) {
 		i_obj->rescode = MEMCACHED_BAD_KEY_PROVIDED;
 		RETURN_FROM_GET;
 	}
@@ -1448,7 +1448,7 @@ static void php_memc_store_impl(INTERNAL_FUNCTION_PARAMETERS, int op, zend_bool
 	MEMC_METHOD_FETCH_OBJECT;
 	i_obj->rescode = MEMCACHED_SUCCESS;
 
-	if (key_len == 0 || strchr(key, ' ')) {
+	if (key_len == 0 || (!memcached_behavior_get(m_obj->memc, MEMCACHED_BEHAVIOR_BINARY_PROTOCOL) && strchr(key, ' '))) {
 		i_obj->rescode = MEMCACHED_BAD_KEY_PROVIDED;
 		RETURN_FALSE;
 	}
@@ -1599,7 +1599,7 @@ static void php_memc_cas_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 	MEMC_METHOD_FETCH_OBJECT;
 	i_obj->rescode = MEMCACHED_SUCCESS;
 
-	if (key_len == 0 || strchr(key, ' ')) {
+	if (key_len == 0 || (!memcached_behavior_get(m_obj->memc, MEMCACHED_BEHAVIOR_BINARY_PROTOCOL) && strchr(key, ' '))) {
 		i_obj->rescode = MEMCACHED_BAD_KEY_PROVIDED;
 		RETURN_FALSE;
 	}
@@ -1717,7 +1717,7 @@ static void php_memc_delete_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 	MEMC_METHOD_FETCH_OBJECT;
 	i_obj->rescode = MEMCACHED_SUCCESS;
 
-	if (key_len == 0 || strchr(key, ' ')) {
+	if (key_len == 0 || (!memcached_behavior_get(m_obj->memc, MEMCACHED_BEHAVIOR_BINARY_PROTOCOL) && strchr(key, ' '))) {
 		i_obj->rescode = MEMCACHED_BAD_KEY_PROVIDED;
 		RETURN_FALSE;
 	}
@@ -1817,7 +1817,7 @@ static void php_memc_incdec_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key,
 	MEMC_METHOD_FETCH_OBJECT;
 	i_obj->rescode = MEMCACHED_SUCCESS;
 
-	if (key_len == 0 || strchr(key, ' ')) {
+	if (key_len == 0 || (!memcached_behavior_get(m_obj->memc, MEMCACHED_BEHAVIOR_BINARY_PROTOCOL) && strchr(key, ' '))) {
 		i_obj->rescode = MEMCACHED_BAD_KEY_PROVIDED;
 		RETURN_FALSE;
 	}