diff --git a/src/sinqController.cpp b/src/sinqController.cpp
index bf0eeb4..73fbc1f 100644
--- a/src/sinqController.cpp
+++ b/src/sinqController.cpp
@@ -71,21 +71,20 @@ asynStatus sinqController::paramLibAccessFailed(asynStatus status,
 // Static pointers (valid for the entire lifetime of the IOC). The number behind
 // the strings gives the integer number of each variant (see also method
 // stringifyAsynStatus)
-static char *asynSuccessStringified = "success";           // 0
-static char *asynTimeoutStringified = "timeout";           // 1
-static char *asynOverflowStringified = "overflow";         // 2
-static char *asynErrorStringified = "error";               // 3
-static char *asynDisconnectedStringified = "disconnected"; // 4
-static char *asynDisabledStringified = "disabled";         // 5
-static char *asynParamAlreadyExistsStringified =
-    "parameter already exists";                                     // 6
-static char *asynParamNotFoundStringified = "parameter not found";  // 7
-static char *asynParamWrongTypeStringified = "wrong type";          // 8
-static char *asynParamBadIndexStringified = "bad index";            // 9
-static char *asynParamUndefinedStringified = "parameter undefined"; // 10
-static char *asynParamInvalidListStringified = "invalid list";      // 11
+const char *asynSuccessStringified = "success";                             // 0
+const char *asynTimeoutStringified = "timeout";                             // 1
+const char *asynOverflowStringified = "overflow";                           // 2
+const char *asynErrorStringified = "error";                                 // 3
+const char *asynDisconnectedStringified = "disconnected";                   // 4
+const char *asynDisabledStringified = "disabled";                           // 5
+const char *asynParamAlreadyExistsStringified = "parameter already exists"; // 6
+const char *asynParamNotFoundStringified = "parameter not found";           // 7
+const char *asynParamWrongTypeStringified = "wrong type";                   // 8
+const char *asynParamBadIndexStringified = "bad index";                     // 9
+const char *asynParamUndefinedStringified = "parameter undefined"; // 10
+const char *asynParamInvalidListStringified = "invalid list";      // 11
 
-char *sinqController::stringifyAsynStatus(asynStatus status) {
+const char *sinqController::stringifyAsynStatus(asynStatus status) {
     // See
     // https://github.com/epics-modules/asyn/blob/master/asyn/asynDriver/asynDriver.h
     // and
diff --git a/src/sinqController.h b/src/sinqController.h
index 07412f4..90588c6 100644
--- a/src/sinqController.h
+++ b/src/sinqController.h
@@ -43,7 +43,7 @@ class epicsShareClass sinqController : public asynMotorController {
     Convert an asynStatus into a descriptive string. This string can then e.g.
     be used to create debugging messages.
      */
-    char *stringifyAsynStatus(asynStatus status);
+    const char *stringifyAsynStatus(asynStatus status);
 
   protected:
     asynUser *lowLevelPortUser_;