diff -urp blt2.4z/src/bltInt.h blt2.4z-tcl8.6/src/bltInt.h
--- blt2.4z/src/bltInt.h	2002-08-22 03:13:12.000000000 +0700
+++ blt2.4z-tcl8.6/src/bltInt.h	2014-05-30 11:07:01.453354590 +0700
@@ -26,6 +26,11 @@
 #ifndef _BLT_INT_H
 #define _BLT_INT_H
 
+#if (TCL_MAJOR_VERSION == 8) && (TCL_MINOR_VERSION < 6)
+#define Tcl_GetStringResult(interp) interp->result
+#define Tcl_SetResult(interp,val,val2) interp->result = val
+#endif
+
 #ifdef WIN32
 #define STRICT
 #define WIN32_LEAN_AND_MEAN
diff -urp blt2.4z/src/bltScrollbar.c blt2.4z-tcl8.6/src/bltScrollbar.c
--- blt2.4z/src/bltScrollbar.c	2002-07-18 05:38:54.000000000 +0700
+++ blt2.4z-tcl8.6/src/bltScrollbar.c	2014-05-30 11:11:20.816689753 +0700
@@ -534,7 +534,7 @@ ScrollbarWidgetCmd(clientData, interp, a
 	} else {
 	    fraction = ((double)pixels / (double)barWidth);
 	}
-	sprintf(interp->result, "%g", fraction);
+	sprintf(Tcl_GetStringResult(interp), "%g", fraction);
     } else if ((c == 'f') && (strncmp(argv[1], "fraction", length) == 0)) {
 	int x, y, pos, barWidth;
 	double fraction;
diff -urp blt2.4z/src/bltTed.c blt2.4z-tcl8.6/src/bltTed.c
--- blt2.4z/src/bltTed.c	2002-05-17 03:46:00.000000000 +0700
+++ blt2.4z-tcl8.6/src/bltTed.c	2014-05-30 11:10:17.774560163 +0700
@@ -1504,7 +1504,7 @@ EditOp(dataPtr, interp, argc, argv)
 	tablePtr->flags |= ARRANGE_PENDING;
 	Tcl_DoWhenIdle(tablePtr->arrangeProc, tablePtr);
     }
-    interp->result = Tk_PathName(tedPtr->tkwin);
+    Tcl_SetResult(interp, Tk_PathName(tedPtr->tkwin), TCL_STATIC);
     tedPtr->flags |= LAYOUT_PENDING;
     EventuallyRedraw(tedPtr);
     return TCL_OK;
@@ -1678,7 +1678,7 @@ SelectOp(dataPtr, interp, argc, argv)
 	    tedPtr->activeRectArr[4].width = grip - 1;
 	    tedPtr->activeRectArr[4].height = grip - 1;
 
-	    interp->result = Tk_PathName(entryPtr->tkwin);
+	    Tcl_SetResult(interp, Tk_PathName(tedPtr->tkwin), TCL_STATIC);
 	    active = 1;
 	    break;
 	}
@@ -1751,7 +1751,7 @@ RepOp(dataPtr, interp, argc, argv)
 	tablePtr->flags |= ARRANGE_PENDING;
 	Tcl_DoWhenIdle(tablePtr->arrangeProc, tablePtr);
     }
-    interp->result = Tk_PathName(tedPtr->tkwin);
+    Tcl_SetResult(interp, Tk_PathName(tedPtr->tkwin), TCL_STATIC);
     tedPtr->flags |= LAYOUT_PENDING;
     EventuallyRedraw(tedPtr);
     return TCL_OK;
diff -urp blt2.4z/src/bltVecMath.c blt2.4z-tcl8.6/src/bltVecMath.c
--- blt2.4z/src/bltVecMath.c	2002-09-10 12:12:33.000000000 +0700
+++ blt2.4z-tcl8.6/src/bltVecMath.c	2014-05-30 11:12:53.846381976 +0700
@@ -764,20 +764,20 @@ MathError(interp, value)
     if ((errno == EDOM) || (value != value)) {
 	Tcl_AppendResult(interp, "domain error: argument not in valid range",
 	    (char *)NULL);
-	Tcl_SetErrorCode(interp, "ARITH", "DOMAIN", interp->result,
+	Tcl_SetErrorCode(interp, "ARITH", "DOMAIN", Tcl_GetStringResult(interp),
 	    (char *)NULL);
     } else if ((errno == ERANGE) || IS_INF(value)) {
 	if (value == 0.0) {
 	    Tcl_AppendResult(interp, 
 			     "floating-point value too small to represent",
 		(char *)NULL);
-	    Tcl_SetErrorCode(interp, "ARITH", "UNDERFLOW", interp->result,
+	    Tcl_SetErrorCode(interp, "ARITH", "UNDERFLOW", Tcl_GetStringResult(interp),
 		(char *)NULL);
 	} else {
 	    Tcl_AppendResult(interp, 
 			     "floating-point value too large to represent",
 		(char *)NULL);
-	    Tcl_SetErrorCode(interp, "ARITH", "OVERFLOW", interp->result,
+	    Tcl_SetErrorCode(interp, "ARITH", "OVERFLOW", Tcl_GetStringResult(interp),
 		(char *)NULL);
 	}
     } else {
@@ -786,7 +786,7 @@ MathError(interp, value)
 	sprintf(buf, "%d", errno);
 	Tcl_AppendResult(interp, "unknown floating-point error, ",
 	    "errno = ", buf, (char *)NULL);
-	Tcl_SetErrorCode(interp, "ARITH", "UNKNOWN", interp->result,
+	Tcl_SetErrorCode(interp, "ARITH", "UNKNOWN", Tcl_GetStringResult(interp),
 	    (char *)NULL);
     }
 }
diff -urp blt2.4z/src/tkScrollbar.c blt2.4z-tcl8.6/src/tkScrollbar.c
--- blt2.4z/src/tkScrollbar.c	2002-05-17 03:46:01.000000000 +0700
+++ blt2.4z-tcl8.6/src/tkScrollbar.c	2014-05-30 11:13:40.004747237 +0700
@@ -533,7 +533,7 @@ ScrollbarWidgetCmd(clientData, interp, a
 	} else {
 	    fraction = ((double)pixels / (double)barWidth);
 	}
-	sprintf(interp->result, "%g", fraction);
+	sprintf(Tcl_GetStringResult(interp), "%g", fraction);
     } else if ((c == 'f') && (strncmp(argv[1], "fraction", length) == 0)) {
 	int x, y, pos, barWidth;
 	double fraction;