diff --git a/library/dhm.c b/library/dhm.c
index 90e5b4b..b6f9b9d 100644
--- a/library/dhm.c
+++ b/library/dhm.c
@@ -75,8 +75,9 @@
     int ret = POLARSSL_ERR_DHM_BAD_INPUT_DATA;
 
     mpi_init( &L ); mpi_init( &U );
-    mpi_lset( &L, 2 );
-    mpi_sub_int( &U, P, 2 );
+
+    MPI_CHK( mpi_lset( &L, 2 ) );
+    MPI_CHK( mpi_sub_int( &U, P, 2 ) );
 
     if( mpi_cmp_mpi( param, &L ) >= 0 &&
         mpi_cmp_mpi( param, &U ) <= 0 )
@@ -84,8 +85,8 @@
         ret = 0;
     }
 
+cleanup:
     mpi_free( &L ); mpi_free( &U );
-
     return( ret );
 }
 
@@ -139,7 +140,7 @@
         mpi_fill_random( &ctx->X, x_size, f_rng, p_rng );
 
         while( mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 )
-            mpi_shift_r( &ctx->X, 1 );
+            MPI_CHK( mpi_shift_r( &ctx->X, 1 ) );
 
         if( count++ > 10 )
             return( POLARSSL_ERR_DHM_MAKE_PARAMS_FAILED );
@@ -225,7 +226,7 @@
         mpi_fill_random( &ctx->X, x_size, f_rng, p_rng );
 
         while( mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 )
-            mpi_shift_r( &ctx->X, 1 );
+            MPI_CHK( mpi_shift_r( &ctx->X, 1 ) );
 
         if( count++ > 10 )
             return( POLARSSL_ERR_DHM_MAKE_PUBLIC_FAILED );