diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 7a7238c..c1071b0 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -3780,7 +3780,7 @@
         goto exit;
     }
 
-    if( !operation->nonce_set )
+    if( !operation->nonce_set || operation->is_encrypt == 0 )
     {
         status = PSA_ERROR_BAD_STATE;
         goto exit;
@@ -3829,7 +3829,7 @@
         goto exit;
     }
 
-    if( !operation->nonce_set )
+    if( !operation->nonce_set || operation->is_encrypt == 1 )
     {
         status = PSA_ERROR_BAD_STATE;
         goto exit;