diff --git a/src/spicelib/devices/hisim2/hsm2eval.c b/src/spicelib/devices/hisim2/hsm2eval.c
index 8316b9869..9a68b08b6 100644
--- a/src/spicelib/devices/hisim2/hsm2eval.c
+++ b/src/spicelib/devices/hisim2/hsm2eval.c
@@ -131,7 +131,7 @@ to others."
 #define C_IDD_MIN    1.0e-15
 
 /* local variables used in macro functions */
-double TMF1 , TMF2 , TMF3 , TMF4 ; 
+static double TMF1 , TMF2 , TMF3 , TMF4 ; 
 /*===========================================================*
 * pow
 *=================*/
diff --git a/src/spicelib/devices/hisimhv1/hsmhveval.c b/src/spicelib/devices/hisimhv1/hsmhveval.c
index c1a800bc4..9a5a48f4b 100644
--- a/src/spicelib/devices/hisimhv1/hsmhveval.c
+++ b/src/spicelib/devices/hisimhv1/hsmhveval.c
@@ -160,7 +160,7 @@ June. 2008  (revised in June 2011)
 #define C_gidl_delta 0.5
 
 /* local variables used in macro functions */
-double TMF0 , TMF1 , TMF2 , TMF3 , TMF4 , TMF5 , TMF6 ; 
+static double TMF0 , TMF1 , TMF2 , TMF3 , TMF4 , TMF5 , TMF6 ; 
 /*===========================================================*
 * pow
 *=================*/