diff --git a/tecsdriv.c b/tecsdriv.c
index f05c172..b214a83 100644
--- a/tecsdriv.c
+++ b/tecsdriv.c
@@ -92,7 +92,7 @@ int TecsWrapper(SConnection * pCon, SicsInterp * pSics, void *pData,
                 int argc, char *argv[])
 {
   pEVControl self = NULL;
-  char pBueffel[256], result[1024], *res;
+  char pBueffel[1024], result[1024], *res;
   int iRet;
   pEVDriver pD;
   pTecsDriv pMe;
@@ -170,7 +170,7 @@ int TecsWrapper(SConnection * pCon, SicsInterp * pSics, void *pData,
       goto Error;
     fVal = atof(result);
     if (argc == 3 && atof(argv[2]) > fVal) {
-      sprintf(pBueffel,
+      snprintf(pBueffel, sizeof pBueffel,
               "WARNING: upper limit reduced to maximal allowed value: %g",
               fVal);
       SCWrite(pCon, pBueffel, eWarning);
@@ -185,7 +185,8 @@ int TecsWrapper(SConnection * pCon, SicsInterp * pSics, void *pData,
       iRet = 1;
     }
     if (iRet) {
-      sprintf(pBueffel, "%s.%s = %s\n", self->pName, argv[1], result);
+      snprintf(pBueffel, sizeof pBueffel,
+               "%s.%s = %s\n", self->pName, argv[1], result);
       SCWrite(pCon, pBueffel, eValue);
     }
     return iRet;
@@ -220,7 +221,8 @@ int TecsWrapper(SConnection * pCon, SicsInterp * pSics, void *pData,
     }
     if (iRet < 0)
       goto Error;
-    sprintf(pBueffel, "%s.%s = %s\n", self->pName, argv[1], result);
+    snprintf(pBueffel, sizeof pBueffel,
+             "%s.%s = %s\n", self->pName, argv[1], result);
     SCWrite(pCon, pBueffel, eValue);
     return 1;
   }