diff --git a/lef/defRead.c b/lef/defRead.c
index 197e086f..8d6853fe 100644
--- a/lef/defRead.c
+++ b/lef/defRead.c
@@ -1498,7 +1498,7 @@ DefReadPins(
 	NULL
     };
 
-    static int lef_class_to_bitmask[] = {
+    static const int lef_class_to_bitmask[] = {
 	PORT_CLASS_DEFAULT,
 	PORT_CLASS_INPUT,
 	PORT_CLASS_TRISTATE,
@@ -1507,7 +1507,7 @@ DefReadPins(
 	PORT_CLASS_FEEDTHROUGH
     };
 
-    static int lef_use_to_bitmask[] = {
+    static const int lef_use_to_bitmask[] = {
 	PORT_USE_DEFAULT,
 	PORT_USE_SIGNAL,
 	PORT_USE_POWER,
diff --git a/lef/defWrite.c b/lef/defWrite.c
index 10205604..ecddf23b 100644
--- a/lef/defWrite.c
+++ b/lef/defWrite.c
@@ -194,7 +194,7 @@ const char *
 defTransPos(
     Transform *t)
 {
-    static const char * def_orient[] = {
+    static const char * const def_orient[] = {
 	"N", "S", "E", "W", "FN", "FS", "FE", "FW"
     };
 
diff --git a/lef/lefRead.c b/lef/lefRead.c
index 424dc94d..6ad92144 100644
--- a/lef/lefRead.c
+++ b/lef/lefRead.c
@@ -311,10 +311,10 @@ LefError(
     static int errors = 0, warnings = 0, messages = 0;
     va_list args;
 
-    char *lefdeftypes[] = {"LEF", "DEF", "techfile lef section"};
+    const char *lefdeftypes[] = {"LEF", "DEF", "techfile lef section"};
 
     int mode, level;
-    char *lefdeftype;
+    const char *lefdeftype;
 
     switch (type) {
 	case LEF_INFO: